Aer Gym Duffel 3 vs Knack Convertible Duffel
The Aer Gym Duffel 3 is 24.1L and 1.32kg2.9lb; the Knack Convertible Duffel is 24L and 1.16kg2.6lb. The Knack Convertible Duffel is 0.16kg0.4lb lighter. The Aer Gym Duffel 3 costs $106 less. The Aer Gym Duffel 3 fits the carry-on limit of 31 of 36 major airlines and the Knack Convertible Duffel fits 36; under the seat, 0 and 0 of 26.
| Spec | Aer Gym Duffel 3 | Knack Convertible Duffel |
|---|---|---|
| Price | $169Best | $275 |
| Volume | 24.1L | 24L |
| Expands to | n/a | 40L |
| Weight | 1.32kg2.9lb | 1.16kg2.6lbBest |
| Carry-on compliance | 86% | 100%Best |
| Personal-item compliance | 0% | 0% |
| Dimensions | 29×43×23cm11.5×17×9in | 33×48.3×12.7cm13×19×5in |
| Laptop | 16"Best | 15.6" |
| Bottle pockets | 2 | 1 |
| Opening | Zippered main compartment | n/a |
| Warranty | Lifetime | n/a |
| Organizer | Yes | Yes |
| Shoe compartment | Yes | No |
| Hydration sleeve | No | No |
| Frame sheet | No | No |
| Water-resistant | No | Yes |
| Rain cover | No | No |
| MOLLE | No | No |
| Hip belt | No | No |
| Sternum strap | No | Removable |
| Load lifters | No | No |
| Shoulder strap | Yes | Removable |
| Luggage pass-through | Yes | Yes |
| Camera compartment | No | No |
| Bike-ready | No | No |
| Material | 1680D CORDURA ballistic nylon exterior, antimicrobial-treated liner, YKK zippers, Duraflex hardware | 420D high-density nylon with PU coating, 840D ballistic nylon bottom, 150D antimicrobial polyester lining |
| Last checked | 2026-09 | 2026-09 |
Where their airline fit differs
| Airline | Limit | Aer Gym Duffel 3 | Knack Convertible Duffel |
|---|---|---|---|
| Air Arabia | Carry-on | Too big | Fits |
| Air India | Carry-on | Too big | Fits |
| Emirates | Carry-on | Too big | Fits |
| Ryanair | Carry-on | Too big | Fits |
| Vueling | Carry-on | Too big | Fits |
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Specs come from each brand's own product page. Fit uses listed dimensions in any orientation. How we score carry-on fit.