Champs Luggage Onyx Daily Backpack vs Mountainsmith Zerk 20 UL Daypack
The Champs Luggage Onyx Daily Backpack is 20L and 0.8kg1.8lb; the Mountainsmith Zerk 20 UL Daypack is 20L and 0.79kg1.7lb. The Mountainsmith Zerk 20 UL Daypack is 0.01kg0lb lighter. The Champs Luggage Onyx Daily Backpack costs $34.94999999999999 less. The Champs Luggage Onyx Daily Backpack fits the carry-on limit of 36 of 36 major airlines and the Mountainsmith Zerk 20 UL Daypack fits 36; under the seat, 7 and 1 of 26.
| Spec | Champs Luggage Onyx Daily Backpack | Mountainsmith Zerk 20 UL Daypack |
|---|---|---|
| Price | $145Best | $179.95 |
| Volume | 20L | 20L |
| Expands to | n/a | 23L |
| Weight | 0.8kg1.8lb | 0.79kg1.7lbBest |
| Carry-on compliance | 100% | 100% |
| Personal-item compliance | 27%Best | 4% |
| Dimensions | 44.5×33×17.1cm17.5×13×6.5in | 45.7×25.4×15.2cm18×10×6in |
| Laptop | 15.6" | no laptop sleeve |
| Bottle pockets | 1 | 2 |
| Opening | n/a | Roll-top, Roll top closure with V-strap compression |
| Warranty | 10 years | Lifetime |
| Torso length | n/a | 38.1 to 48.3cm (15 to 19in) |
| Organizer | Yes | No |
| Shoe compartment | No | No |
| Hydration sleeve | No | Yes |
| Frame sheet | No | Removable |
| Water-resistant | Yes | No |
| Rain cover | No | No |
| MOLLE | No | No |
| Hip belt | No | Removable |
| Sternum strap | No | Yes |
| Load lifters | No | No |
| Shoulder strap | No | No |
| Luggage pass-through | Yes | No |
| Camera compartment | No | No |
| Material | Water-resistant nylon | 210D and 100D Robic nylon X-Grid Extreema (UHMWPE) ripstop with UTS coating, 840D x 100D stretch mesh, 150D polyester liner |
| Last checked | 2026-10 | 2026-09 |
Where their airline fit differs
| Airline | Limit | Champs Luggage Onyx Daily Backpack | Mountainsmith Zerk 20 UL Daypack |
|---|---|---|---|
| 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 |
| 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.