Rugged Radios Expand to 4 Place STX Headset Expansion Kits STX Stereo Behind The Head HC712120 These modules are sealed to Size:6 5 8 (53) These modules are sealed to create an Ingress Protection Rating of IP68 which will keep moisture out of your fixtures from exposure to pressurized water spray and brief underwater submersions black Powdercoat and profiled to keep weight at a minimum without compromising strength or durability With nearly 30 years experience in manufacturing high noise environment communications Pit Stop USA offers Rugged Expand to 4 Place STX Headset Expansion Kits STX Stereo Behind The Head PLUS2 STX BTU at low everyday prices