Gossamer Gear Grit 28 Fastpack vs Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L
The Gossamer Gear Grit 28 Fastpack is 28L and 0.46kg1lb; the Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L is 28L and 0.44kg1lb. The Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L is 0.02kg0lb lighter. The Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L costs $154.01 less. The Gossamer Gear Grit 28 Fastpack fits the carry-on limit of 36 of 36 major airlines and the Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L fits 36; under the seat, 0 and 1 of 26.
| Spec | Gossamer Gear Grit 28 Fastpack | Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L |
|---|---|---|
| Price | $180 | $25.99Best |
| Volume | 28L | 28L |
| Weight | 0.46kg1lb | 0.44kg1lbBest |
| Carry-on compliance | 100% | 100% |
| Personal-item compliance | 0% | 4%Best |
| Dimensions | 48.3×27.9×14.6cm19×11×5.5in | 46×31×20cm18×12×8in |
| Laptop | no laptop sleeve | n/a |
| Compartments | 1 | n/a |
| Bottle pockets | n/a | 2 |
| Opening | Roll-top, Roll top fastened down the sides | Main compartment pocket |
| Warranty | 1 year | 10 years |
| Organizer | No | No |
| Shoe compartment | No | No |
| Hydration sleeve | Yes | No |
| Frame sheet | No | No |
| Water-resistant | No | No |
| Rain cover | No | No |
| MOLLE | No | No |
| Hip belt | Insert sold separately | No |
| Sternum strap | Yes | Yes |
| Load lifters | No | No |
| Shoulder strap | No | No |
| Luggage pass-through | No | No |
| Camera compartment | No | No |
| Material | Riptide Ripstop 100D recycled Robic nylon, UHMWPE stretch mesh, PFAS free | Nylon, polyester lining |
| Last checked | 2026-09 | 2026-10 |
Where their airline fit differs
| Airline | Limit | Gossamer Gear Grit 28 Fastpack | Waterfly TransformerX 5.0 UltraLight Packable Backpack 28L |
|---|---|---|---|
| Frontier Airlines | 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.