"The world’s most hostile environments are our proving grounds”…has been the APM Hexseal mission and motto since 1947 when APM first developed its line of switch and circuit breaker,  high-pressure, sealing boots for the U.S Navy. APM’s highly IP Rated seals are designed to meet MIL-B-5423, are UL Recognized, and millions have been used extensively in avionics, instrumentation, communications, construction, marine, medical, and industrial and process industries. APM also offers a full line of UL recognized self-sealing fasteners & washers for panel, electrical NEMA enclosure and other related systems requiring sealing to 20,000psig that are also impervious to a wide range of corrosive liquids and gases.