PelicanTM protector cases are designed rugged and travel the harshest environments Against the extreme cold of the artic or the heat of battle, Pelican cases have survived These tough cases are designed with an automatic purge valve that equalizes air pressure, a watertight silicone O-ring lid, over-molded rubber handles and stainless steel hardware Strong polyurethane wheels with stainless steel bearings Watertight, crushproof, and dustproof Automatic pressure equalization valve balances interior pressure, keeps water out Comfortable rubber over-molded top and side handles Has easy open double throw latches.