It’s beefy enough to be used outside of a larger protective case, but compact enough to slide into Conterra's larger kits such as the infinity jump or responder IV. It is versatile enough to use on its own for basic oxygen administration. Double decker design is very space efficient for use as a module in a larger kit. The O-2 caddy’s padded top pocket fits an aluminum or steel "D" cylinder with regulator in place. The bottom compartment is for storing your basic airway tools. Built entirely out of Ballistics Nylon, lightly padded. Oxygen cylinder and medical supplies not included.