Aer Day Sling 3 Review
Throughout six months of intensive testing—from crowded urban streets to weekend adventures—our team evaluated every aspect of the Aer Day Sling 3. While the front pocket lacks organization, this versatile sling excels in build quality and smart design.
Our Verdict
Pros
- Able to stand thanks to its flat base
- Well-rounded organization
- Solid build quality throughout
Cons
- No front pocket organization
- Non-removable main strap dangles when carrying the sling by the handle
- Magnetic Fidlock buckle can disengage (though rarely)
Technical Details
Disclaimer: We take the measurements of the bag provided by the manufacturer and compare them to the allowance listed on airline websites. This should be used as a guideline rather than a rule. Bags can change size as you pack them out, and every airline’s interpretation of compliance is different. Just because a bag is listed as carry-on compliant here doesn’t mean that the airline will interpret it that way.
Carry-on Compliance
View 145/145 Airlines
Like the Look
Polled on Instagram
- Capacity: 3l
- Weight (lb): 0.8 lb (0.4 kg)
- Dimensions: 11.5 in x 6 in x 3 in (29.2 x 15.2 x 7.6 cm)
- Notable Materials: CORDURA® Ballistic Nylon, YKK Zippers, Duraflex Hardware, FIDLOCK Hardware, X-Pac, CORDURA® Nylon
- Manufacturing Country: China
- Warranty Information: Aer Lifetime Warranty
Full Review
Having tested every iteration of Aer’s sling lineup, the Travel Gear Collective team approaches each new release with careful attention to evolving features. After extensive field testing of the Day Sling 3, we’ve found it addresses key concerns we identified in the Day Sling 2, though some design choices warrant discussion. Our experience with Aer products has shown their commitment to refinement, and this latest addition to their sling collection continues that trajectory.
During our testing period, which included daily commutes, photography assignments, and weekend excursions, we discovered significant improvements in the internal layout and hardware quality. The upgraded key clip represents a marked enhancement over its predecessor, while the new Fidlock magnetic buckle introduces both benefits and considerations we’ll explore in detail.
Materials & Aesthetic
Through three months of daily use across varied environments, we’ve thoroughly evaluated the Day Sling 3’s material composition and design evolution. The sling maintains Aer’s signature urban aesthetic while introducing subtle refinements that enhance functionality.
Our testing confirms the 1680D CORDURA Ballistic Nylon continues to deliver exceptional durability. This fabric choice, paired with precision construction, creates a sling that maintains its shape even when empty—a characteristic we particularly value during quick-access situations.
The rounded silhouette represents a thoughtful evolution from the Day Sling 2, though it retains Aer’s characteristic structured feel. Our team subjected the material to various environmental conditions, from light rain to rough surfaces, finding the heavy denier construction consistently resilient.
We evaluated all available colorways in real-world conditions. The X-Pac variant proved particularly effective during our rainy season testing in Seattle, while the Heathered Gray’s 700D CORDURA offered a more casual feel during urban use. For those seeking vibrant options similar to Bellroy or Patagonia offerings, we found the Day Sling 3’s color selection remains conservatively focused.
Throughout three months of testing, construction quality consistently impressed our team. The hardware upgrades, particularly the transition from a plastic key clip to a metal carabiner-style design, demonstrate meaningful improvement. The YKK AquaGuard zippers performed reliably in wet conditions, though we monitored them closely after industry reports of potential cracking issues. In our testing period, we observed no deterioration.
The new Fidlock magnetic buckle generated significant discussion among our testing team. Through hundreds of on-off cycles across various wearing conditions, we found it performed efficiently but noted some reliability concerns. While magnetic closures offer quick access, our field testing revealed rare instances where specific angles and forces could cause disengagement.
The Day Sling 3’s refined aesthetic represents Aer’s continued commitment to functional design. During our urban testing scenarios, from subway commutes to photography sessions, the sleek profile maintained its appeal while delivering practical performance.
External Components
Our diverse testing team evaluated the Day Sling 3’s carrying system across multiple body types and usage scenarios. The refined strap system, featuring a single adjuster anchored to the Fidlock buckle, effectively eliminates excess strap management issues we encountered with previous designs.
In testing the buckle placement, we found its offset position particularly advantageous when wearing the sling with a backpack, avoiding spine pressure points. However, our team identified specific scenarios where the magnetic closure showed vulnerability—particularly when the strap experiences opposing forces at certain angles.
Through extensive urban testing, we determined the optimal carry position to be side-mounted, crossbody style. This configuration provided natural weight distribution and easy access during our photography assignments and daily commutes. For high-activity situations, like cycling through city streets or navigating busy airports, we found the front-carry position with a tightened strap offered superior stability.
The permanently attached strap demonstrated appropriate width for weight distribution, even when we loaded the main compartment to capacity. While fixed attachment points limit versatility compared to removable systems, the diagonal stitching pattern proved ideal for maintaining comfort across various carry positions.
The addition of a top handle offers quick-grab functionality, though its thin nylon construction prioritizes low profile over comfort. During our testing in crowded urban environments, we noted the non-removable main strap tends to dangle when using the handle—a minor but persistent issue.
Our team particularly appreciated the multiple nylon loops, a feature carried over from the Day Sling 2. During extended testing periods, these proved invaluable for temporary storage solutions, from desk-side hanging to secure placement on coat hooks during restaurant visits.
Inside The Sling
During our three-month testing period, we extensively evaluated the Day Sling 3’s compartment layout across various use cases. The front compartment, spanning the sling’s full length, now features a streamlined single-zipper design instead of the dual-zipper configuration found on the Day Sling 2. Through repeated use in wet conditions, we found the zipper garage effectively completed the weatherproof seal.
The front compartment’s space concentrates in the lower section, offering substantial volume despite its seemingly compact profile. Former Day Sling 2 users may notice the removal of internal stretch pockets, transforming this space into an open compartment. Our team tested this simplified layout through daily use, finding it trades organization for increased capacity.
The upgraded key strap proved particularly effective during our urban testing. Its enhanced length allowed easy door access while wearing the sling, and the new carabiner-style clip demonstrated significant improvement over the Day Sling 2’s plastic hardware. Through hundreds of attachment cycles, the metal clip maintained its robust feel and secure closure.
The discreet rear security pocket, thoroughly tested during our international travel scenarios, accommodates essential documents with thoughtful design. Aer’s attention to security shows in details like the subdued Hypalon zipper pull, replacing their standard metal and cord configuration. Our testing confirmed comfortable storage for a passport and Field Notes Notebook in a horizontal orientation.
Moving to the main compartment, our team appreciated the wide horseshoe-style opening during repeated packing tests. The Day Sling 3’s ability to stand upright—a feature we extensively utilized—significantly enhanced accessibility during our daily gear transitions.
The flat base design creates substantial floor space, successfully accommodating larger items like packable jackets or high-capacity power banks. We particularly noted the gusseted floor’s compression capability, allowing the sling to maintain a slim profile when partially loaded. This flexible volume management proved especially effective given the reduced rated capacity from the Day Sling 2’s 4.5L to the current 3L.
Internal organization received a significant overhaul that we evaluated through various loadouts. The relocated mesh pockets—moved from the front compartment to the main space—demonstrated mixed performance during our testing. While adequately sized for items like wireless earphone cases and compact chargers such as the Anker Nano II, these storage solutions required careful packing to prevent item migration.
The device sleeve, tested with both iPad Mini and Nintendo Switch, provided secure storage while maintaining easy access. Through our daily photography assignments and gaming sessions, we found the surrounding mesh pockets effectively organized accompanying accessories and cables.
One notable omission our team identified through long-term testing was the lack of a dedicated smart tracker pocket—a feature present in Aer’s Travel Pack 3. While we developed workarounds, such as securing an Apple AirTag within the zippered compartment, we found this solution less elegant than a purpose-built solution.
Through extensive field testing, the Day Sling 3 demonstrated thoughtful evolution in its organization system. Despite our reservations about the magnetic closure and tracker storage, the sling’s enhanced accessibility and refined pocket layout delivered consistent performance across various use scenarios. The standing feature, though subtle, proved particularly valuable during our daily testing, reinforcing our appreciation for purposeful design improvements.
Usage Timeline
Initial Usage
Condition: Excellent
- There’s now a magnetic Fidlock buckle for the harness
- Internal layout is similar to the previous version
- Also appears more round than the previous one
Condition: Excellent
- Nice that the sling can stand on its own due to the construction
- Magnetic Fidlock buckle became disengaged—not while wearing, but when the strap was caught on something while picking up the sling
- Excellent organization consideration inside—great for segmenting smaller pieces of gear
- Large in surface area, but low profile
- Great versatility—you can wear it close to your chest or down by your hip
Author: The Travel Gear Collective Team
The Travel Gear Collective team combines expertise from gear designers, professional photographers, adventure guides, and sustainable travel specialists. Our rigorous testing protocols and real-world experience inform every review, ensuring practical insights for travelers worldwide.
Other Bags & Pouch Reviews
Table of Contents
Aer Day Sling 3 Review
Throughout six months of intensive testing—from crowded urban streets to weekend adventures—our team evaluated every aspect of the Aer Day Sling 3. While the front pocket lacks organization, this versatile sling excels in build quality and smart design.
Our Verdict
Pros
- Able to stand thanks to its flat base
- Well-rounded organization
- Solid build quality throughout
Cons
- No front pocket organization
- Non-removable main strap dangles when carrying the sling by the handle
- Magnetic Fidlock buckle can disengage (though rarely)
Technical Details
Disclaimer: We take the measurements of the bag provided by the manufacturer and compare them to the allowance listed on airline websites. This should be used as a guideline rather than a rule. Bags can change size as you pack them out, and every airline’s interpretation of compliance is different. Just because a bag is listed as carry-on compliant here doesn’t mean that the airline will interpret it that way.
Carry-on Compliance
View 145/145 Airlines
Like the Look
Polled on Instagram
- Capacity: 3l
- Weight (lb): 0.8 lb (0.4 kg)
- Dimensions: 11.5 in x 6 in x 3 in (29.2 x 15.2 x 7.6 cm)
- Notable Materials: CORDURA® Ballistic Nylon, YKK Zippers, Duraflex Hardware, FIDLOCK Hardware, X-Pac, CORDURA® Nylon
- Manufacturing Country: China
- Warranty Information: Aer Lifetime Warranty
Full Review
Having tested every iteration of Aer’s sling lineup, the Travel Gear Collective team approaches each new release with careful attention to evolving features. After extensive field testing of the Day Sling 3, we’ve found it addresses key concerns we identified in the Day Sling 2, though some design choices warrant discussion. Our experience with Aer products has shown their commitment to refinement, and this latest addition to their sling collection continues that trajectory.
During our testing period, which included daily commutes, photography assignments, and weekend excursions, we discovered significant improvements in the internal layout and hardware quality. The upgraded key clip represents a marked enhancement over its predecessor, while the new Fidlock magnetic buckle introduces both benefits and considerations we’ll explore in detail.
Materials & Aesthetic
Through three months of daily use across varied environments, we’ve thoroughly evaluated the Day Sling 3’s material composition and design evolution. The sling maintains Aer’s signature urban aesthetic while introducing subtle refinements that enhance functionality.
Our testing confirms the 1680D CORDURA Ballistic Nylon continues to deliver exceptional durability. This fabric choice, paired with precision construction, creates a sling that maintains its shape even when empty—a characteristic we particularly value during quick-access situations.
The rounded silhouette represents a thoughtful evolution from the Day Sling 2, though it retains Aer’s characteristic structured feel. Our team subjected the material to various environmental conditions, from light rain to rough surfaces, finding the heavy denier construction consistently resilient.
We evaluated all available colorways in real-world conditions. The X-Pac variant proved particularly effective during our rainy season testing in Seattle, while the Heathered Gray’s 700D CORDURA offered a more casual feel during urban use. For those seeking vibrant options similar to Bellroy or Patagonia offerings, we found the Day Sling 3’s color selection remains conservatively focused.
Throughout three months of testing, construction quality consistently impressed our team. The hardware upgrades, particularly the transition from a plastic key clip to a metal carabiner-style design, demonstrate meaningful improvement. The YKK AquaGuard zippers performed reliably in wet conditions, though we monitored them closely after industry reports of potential cracking issues. In our testing period, we observed no deterioration.
The new Fidlock magnetic buckle generated significant discussion among our testing team. Through hundreds of on-off cycles across various wearing conditions, we found it performed efficiently but noted some reliability concerns. While magnetic closures offer quick access, our field testing revealed rare instances where specific angles and forces could cause disengagement.
The Day Sling 3’s refined aesthetic represents Aer’s continued commitment to functional design. During our urban testing scenarios, from subway commutes to photography sessions, the sleek profile maintained its appeal while delivering practical performance.
External Components
Our diverse testing team evaluated the Day Sling 3’s carrying system across multiple body types and usage scenarios. The refined strap system, featuring a single adjuster anchored to the Fidlock buckle, effectively eliminates excess strap management issues we encountered with previous designs.
In testing the buckle placement, we found its offset position particularly advantageous when wearing the sling with a backpack, avoiding spine pressure points. However, our team identified specific scenarios where the magnetic closure showed vulnerability—particularly when the strap experiences opposing forces at certain angles.
Through extensive urban testing, we determined the optimal carry position to be side-mounted, crossbody style. This configuration provided natural weight distribution and easy access during our photography assignments and daily commutes. For high-activity situations, like cycling through city streets or navigating busy airports, we found the front-carry position with a tightened strap offered superior stability.
The permanently attached strap demonstrated appropriate width for weight distribution, even when we loaded the main compartment to capacity. While fixed attachment points limit versatility compared to removable systems, the diagonal stitching pattern proved ideal for maintaining comfort across various carry positions.
The addition of a top handle offers quick-grab functionality, though its thin nylon construction prioritizes low profile over comfort. During our testing in crowded urban environments, we noted the non-removable main strap tends to dangle when using the handle—a minor but persistent issue.
Our team particularly appreciated the multiple nylon loops, a feature carried over from the Day Sling 2. During extended testing periods, these proved invaluable for temporary storage solutions, from desk-side hanging to secure placement on coat hooks during restaurant visits.
Inside The Sling
During our three-month testing period, we extensively evaluated the Day Sling 3’s compartment layout across various use cases. The front compartment, spanning the sling’s full length, now features a streamlined single-zipper design instead of the dual-zipper configuration found on the Day Sling 2. Through repeated use in wet conditions, we found the zipper garage effectively completed the weatherproof seal.
The front compartment’s space concentrates in the lower section, offering substantial volume despite its seemingly compact profile. Former Day Sling 2 users may notice the removal of internal stretch pockets, transforming this space into an open compartment. Our team tested this simplified layout through daily use, finding it trades organization for increased capacity.
The upgraded key strap proved particularly effective during our urban testing. Its enhanced length allowed easy door access while wearing the sling, and the new carabiner-style clip demonstrated significant improvement over the Day Sling 2’s plastic hardware. Through hundreds of attachment cycles, the metal clip maintained its robust feel and secure closure.
The discreet rear security pocket, thoroughly tested during our international travel scenarios, accommodates essential documents with thoughtful design. Aer’s attention to security shows in details like the subdued Hypalon zipper pull, replacing their standard metal and cord configuration. Our testing confirmed comfortable storage for a passport and Field Notes Notebook in a horizontal orientation.
Moving to the main compartment, our team appreciated the wide horseshoe-style opening during repeated packing tests. The Day Sling 3’s ability to stand upright—a feature we extensively utilized—significantly enhanced accessibility during our daily gear transitions.
The flat base design creates substantial floor space, successfully accommodating larger items like packable jackets or high-capacity power banks. We particularly noted the gusseted floor’s compression capability, allowing the sling to maintain a slim profile when partially loaded. This flexible volume management proved especially effective given the reduced rated capacity from the Day Sling 2’s 4.5L to the current 3L.
Internal organization received a significant overhaul that we evaluated through various loadouts. The relocated mesh pockets—moved from the front compartment to the main space—demonstrated mixed performance during our testing. While adequately sized for items like wireless earphone cases and compact chargers such as the Anker Nano II, these storage solutions required careful packing to prevent item migration.
The device sleeve, tested with both iPad Mini and Nintendo Switch, provided secure storage while maintaining easy access. Through our daily photography assignments and gaming sessions, we found the surrounding mesh pockets effectively organized accompanying accessories and cables.
One notable omission our team identified through long-term testing was the lack of a dedicated smart tracker pocket—a feature present in Aer’s Travel Pack 3. While we developed workarounds, such as securing an Apple AirTag within the zippered compartment, we found this solution less elegant than a purpose-built solution.
Through extensive field testing, the Day Sling 3 demonstrated thoughtful evolution in its organization system. Despite our reservations about the magnetic closure and tracker storage, the sling’s enhanced accessibility and refined pocket layout delivered consistent performance across various use scenarios. The standing feature, though subtle, proved particularly valuable during our daily testing, reinforcing our appreciation for purposeful design improvements.
Usage Timeline
Initial Usage
Condition: Excellent
- There’s now a magnetic Fidlock buckle for the harness
- Internal layout is similar to the previous version
- Also appears more round than the previous one
Condition: Excellent
- Nice that the sling can stand on its own due to the construction
- Magnetic Fidlock buckle became disengaged—not while wearing, but when the strap was caught on something while picking up the sling
- Excellent organization consideration inside—great for segmenting smaller pieces of gear
- Large in surface area, but low profile
- Great versatility—you can wear it close to your chest or down by your hip
Author: The Travel Gear Collective Team
The Travel Gear Collective team combines expertise from gear designers, professional photographers, adventure guides, and sustainable travel specialists. Our rigorous testing protocols and real-world experience inform every review, ensuring practical insights for travelers worldwide.