Aer City Pack Pro 2 20L vs Alpha One Niner Whitley Backpack
The Aer City Pack Pro 2 20L is 20L and 1.24kg2.7lb; the Alpha One Niner Whitley Backpack is 20L and 1.21kg2.7lb. The Alpha One Niner Whitley Backpack is 0.03kg0.1lb lighter. The Aer City Pack Pro 2 20L costs $20 less. The Aer City Pack Pro 2 20L fits the carry-on limit of 36 of 36 major airlines and the Alpha One Niner Whitley Backpack fits 36; under the seat, 7 and 0 of 26.
| Spec | Aer City Pack Pro 2 20L | Alpha One Niner Whitley Backpack |
|---|---|---|
| Price | $199Best | $219 |
| Volume | 20L | 20L |
| Weight | 1.24kg2.7lb | 1.21kg2.7lbBest |
| Carry-on compliance | 100% | 100% |
| Personal-item compliance | 27%Best | 0% |
| Dimensions | 44.5×30.5×18cm17.5×12×7in | 47×27.9×15.2cm18.5×11×6in |
| Laptop | 16" | 16" |
| Bottle pockets | 1 | n/a |
| Opening | Clamshell, clamshell (lay-flat main compartment) | main compartment zip, quick access zip behind carry handle |
| Warranty | Lifetime | 5 years |
| Organizer | Yes | Yes |
| Shoe compartment | No | No |
| Hydration sleeve | No | No |
| Frame sheet | No | No |
| Water-resistant | No | No |
| Rain cover | No | No |
| MOLLE | No | No |
| Hip belt | No | No |
| Sternum strap | No | Removable |
| Load lifters | No | No |
| Shoulder strap | No | No |
| Luggage pass-through | Yes | Yes |
| Camera compartment | No | No |
| Material | 1680D CORDURA ballistic nylon exterior (bluesign approved), ripstop nylon interior (bluesign approved), YKK zippers, Duraflex hardware | Dimension-Polyant X42, 500D or 1050D ballistic nylon with 200D Crimson Wave lining |
| Last checked | 2026-09 | 2026-09 |
Where their airline fit differs
| Airline | Limit | Aer City Pack Pro 2 20L | Alpha One Niner Whitley Backpack |
|---|---|---|---|
| Allegiant Air | Personal item | Fits | Too big |
| American Airlines | Personal item | Fits | Too big |
| British Airways | Personal item | Fits | Too big |
| easyJet | Personal item | Fits | Too big |
| Frontier Airlines | Personal item | Fits | Too big |
| LATAM Airlines | Personal item | Fits | Too big |
| Volaris | Personal item | Fits | Too big |
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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.