JPL Element BT500D Bluetooth wireless binaural headset. With interchangeable headband to switch between dual speaker to single speaker, providing a choice of wearing styles. Comfortable for all day wear with 57mm leatherette ear cushions. Wideband enabled speakers with Sound Shield hearing protection. With 'put and stay' ratchet microphone boom arm. 20 hours talk time. Controls on the headset include; call answer/end, volume, microphone mute.