Measure the compartment you will use
Use the internal width, depth and height of your bag. Wheels, handles and lining can take space away from the published external measurements. Mark any curved or tapered section. Decide whether you want 1 large pouch or separate pouches you can remove independently.
Compare dimensions and packing volume
Eagle Creek lists the Pack-It Reveal Cube S at 25 × 18 × 8 cm externally, with a calculated capacity of 3 L. Its page notes that sewing tolerances can change actual dimensions and volume slightly. A capacity figure describes a different property from the footprint needed inside a bag.
Check the loaded pouch
The items you pack can change the shape of a soft pouch. Check how the zip closes and whether the pouch can be removed without emptying the bag. This comparison is a planning method, with no packing test, airline baggage approval or UK delivery claim.
Sources and scope
Manufacturer information checked 11 October 2026. The measuring methods are HeyPikka’s planning suggestions; they do not establish installation or suitability.