Made of high quality, tough black nylon, encasing a light weight, white polyethylene foam that features low water absorption and is fairly rigid (good impact strength). The two grommeted ventilation holes seen in the photo are on both sides of the bag. A large elastic topped pocket is on each side, for holding tool kits, checklists, logbooks, spares, etc. (There are no inside pockets). The bag handles are 1” wide straps of black polyester webbing. The bag closes up with two, large YKK zippers. We do not recommend the 500-901 helmet bag as a shipping container or packaging for your Kirby Morgan life support equipment!