1650 Protector Case4 strong polyurethane wheels with stainless steel bearings Watertight, crushproof, and dustproof Automatic Pressure Equalization Valve balances interior pressure, keeps water out Easy open Double Throw latches Fold down handles O ring seal Open cell core with solid wall design strong, light weight Retractable extension handle Stainless steel hardware and padlock protectors Sensitive equipment needs protection, and since 1976 the answer has been the