The Shure 514B is an omnidirectional, low-impedance handheld microphone with a push-to-talk switch. The microphone is designed with a tough, high-impact enclosure for use in industrial and commercial applications such as dispatch, law enforcement, construction, forestry, transportation and mobile public address applications. The 514B connects to microphone inputs rated at 19 to 300 ohms. It can be used in applications that require long cable lengths or where severe hum noise is present. The microphone includes three mounting clips and the coiled cable provides four conductor lead wires for connecting the microphone and switching relay.