Terraphone Professional intercom systems. These kits feature noise cancelling microphones for improved sound reproduction, an output socket to go to a tape recorder (ideal for recording pacenotes), an optional interface kit to allow connection with 2 way radio setups and a separate on/off switch, thus allowing microphone/headset volumes to be left unaltered upon switching off/on. These systems are installed and wired into your vehicle's 12v supply and come with choice of Professional spec headsets, depending on the helmets you have. Terraphone Clubman and Professional amplifiers are not compatible with Peltor headsets or helmets unless adaptors are used. This Kit includes 2 x Practise headsets, a mobile connection lead and a Terraphone Professional intercom. with noise cancelling microphones Output socket to enable recording of pace notes etc Separate on/off switch so volumes remain unaltered Designed for directly wiring into the 12v car system