The Standard CMP460 is a remote speaker/microphone designed to be used with most Standard handheld VHF radios, including the following models: HX280S, HX370S, HX370SAS, HX471X, HX500S-Li, HX751, HX851, and HX760SBTK. It allows communication while the radio is in a holster or clipped to the user"s belt. The speaker/mic can be positioned close to the operator"s ear to allow contant monitoring of the radio"s receiver. The unit is intrinsically safe for use in hazardous environments.