backpack organizer travel 500 30 L Designed to fit inside most standard backpacks and carry Travel Organizer Insert for Backpack

The 55L (there are other sizes available ) has a massive main compartment when the sides are buckled down in duffel mode, but when not battened down, it expands to 75L (more if you dont mind gear poking out above the lip)

Capacity options: 40L, 55L, 70L, and 100L The Black Hole bags are available in several sizes (40, 55, 70, and 100 litres) to suit different travel needs: The 40-liter model is compact and lightweight, perfect for gym sessions or day trips, with enough room for a change of clothes, shoes, and accessories without being cumbersome

Lower Limit : This is the lowest temperature at which a standard man or warm sleeper can sleep for eight hours without waking due to frigid temperatures

There is also a small mesh pocket on one shoulder strap