Two Helikon water bottles/canteens fit into the middle largest compartment: 500 ml (about 550) and 700 ml (about 750) 😀; as an alternative, two regular 500 ml store-bought water bottles fit just fine too 😀. The main middle compartment has a pocket on the back panel, and another pocket with mesh elastic on the flap. On the outside, in the central section, one side has a fastening system and there is a full-length pocket there, big enough to fit a complete set of cutlery. On the other side there is a MOLLE panel for attaching it, as in my setup with a backpack, where inside there is a pocket closed at the bottom with hook-and-loop, which creates either a closed space or the option to insert, for example, a folding shovel or even a hatchet 😀. There are also side pockets with zippers, and inside they have mesh pockets. Overall, it holds quite a lot and can be attached to a backpack, or carried separately on a strap or belt, because there are buckles for attaching it, plus they can be tucked away so they are not visible. At the very top there is also a ring/loop for tying or attaching something 😀. For me, it is a nice pouch. And there is plenty of room to stash small items 😀.