ProX XM-4UHW UltronX 4U Rack Air Tight Water Sealed ABS CaseProX XM 4UHW UltronX series cases are made from an extremely tough Polypropylene Copolymer, these cases are crush resistant and virtually indestructible. This rugged case now features a pull out handle for flight style travel and easy rolling on ABS wheels against tough street terrain. sealed ring, which makes it Airtight and Watertight. This state of the art airline friendly case is a lightweight design that protects your gear like a hard case. It