STM Prime vs. Tortuga Daypack Pro
Two carry-on travel backpacks, compared spec for spec.
STM Prime
| Capacity | 15 L |
| Weight | 0.7 kg |
| Dimensions | 42×26×13 cm |
| Airline fit | 96% |
| Price | $80 |
Feature by feature
| STM Prime | Feature | Tortuga Daypack Pro |
|---|---|---|
| Storage | ||
| N | Compression | N |
| None | Expanded Capacity | None |
| 0 | Opening | 0 |
| top | Passport | top |
| N | Passthrough | N |
| Carry | ||
| Y | Backpack | Y |
| N | Hip Belt | N |
| Y | Sternum Strap | Y |
| Inside | ||
| 13in | Laptop | 16in |
| 2 | Main Compartments | 2 |
| N | Organizer | N |
| Outside | ||
| × | Hard Shell | × |
| N | Rain-fly | N |
| 2, side | Water Bottle Holder | 2, side |
| Y | Water Resistant | Y |
| Material | |
| Polyester | ECOPAK™ EPX70RS waterproof sailcloth |
Tortuga Daypack Pro
| Capacity | 21 L |
| Weight | 0.5 kg |
| Dimensions | 44×30×17 cm |
| Airline fit | 95% |
| Price | $125 |
Key differences between the STM Prime and Tortuga Daypack Pro
- Laptop sleeve: 13in on the STM Prime; 16in on the Tortuga Daypack Pro.
Both have: passport pocket, backpack straps, sternum strap, water bottle pockets, water resistant.
Which airlines take each bag as a carry-on
We checked both bags against the carry-on size limits of 189 airlines. 180 accept both. 1 accept only the STM Prime, and 0 accept only the Tortuga Daypack Pro.
Only the STM Prime fits
Great Lakes Airlines.
STM Prime vs. Tortuga Daypack Pro: which should you pack?
The Tortuga Daypack Pro carries 6L more than the STM Prime (15L vs. 21L), while the Tortuga Daypack Pro is the lighter pack at 0.5kg (vs. 0.7kg). For carry-on flexibility, the STM Prime fits 96% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Tortuga Daypack Pro; if you want to travel lighter, the Tortuga Daypack Pro is the better call.