Gossamer Gear RikSak vs Waterfly TransformerX Ultralight Packable Backpack 20L
The Gossamer Gear RikSak is 20L and 0.14kg0.3lb; the Waterfly TransformerX Ultralight Packable Backpack 20L is 20L and 0.29kg0.6lb. The Gossamer Gear RikSak is 0.15kg0.3lb lighter. The Waterfly TransformerX Ultralight Packable Backpack 20L costs $19.01 less. The Gossamer Gear RikSak fits the carry-on limit of 35 of 36 major airlines and the Waterfly TransformerX Ultralight Packable Backpack 20L fits 36; under the seat, 0 and 9 of 26.
| Spec | Gossamer Gear RikSak | Waterfly TransformerX Ultralight Packable Backpack 20L |
|---|---|---|
| Price | $45 | $25.99Best |
| Volume | 20L | 20L |
| Weight | 0.14kg0.3lbBest | 0.29kg0.6lb |
| Carry-on compliance | 97% | 100%Best |
| Personal-item compliance | 0% | 35%Best |
| Dimensions | 53.3×32.4×8.9cm21×13×3.5in | 42.9×29×14cm17×11.5×5.5in |
| Laptop | no laptop sleeve | n/a |
| Compartments | 1 | n/a |
| Bottle pockets | n/a | 2 |
| Opening | Top-loading, Easy cinch top with pull tab | Zippered main compartment |
| Warranty | 1 year | 10 years |
| Organizer | No | No |
| Shoe compartment | No | 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 | Yes |
| Load lifters | No | No |
| Shoulder strap | No | No |
| Luggage pass-through | No | No |
| Camera compartment | No | No |
| Bike-ready | No | No |
| Material | 70D recycled Robic nylon, nylon/span stretch mesh, polyester airmesh straps, PFAS free | Tear-resistant, water-resistant nylon, polyester lining |
| Last checked | 2026-09 | 2026-10 |
Where their airline fit differs
| Airline | Limit | Gossamer Gear RikSak | Waterfly TransformerX Ultralight Packable Backpack 20L |
|---|---|---|---|
| Air Canada | Personal item | Too big | Fits |
| Allegiant Air | Personal item | Too big | Fits |
| American Airlines | Personal item | Too big | Fits |
| British Airways | Personal item | Too big | Fits |
| easyJet | Personal item | Too big | Fits |
| Frontier Airlines | Personal item | Too big | Fits |
| JetBlue Airways | Personal item | Too big | Fits |
| LATAM Airlines | Personal item | Too big | Fits |
| Qatar Airways | Carry-on | Too big | Fits |
| Volaris | Personal item | 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.