Cut the music on the internal or external HP as soon as the VHF receivz a signal. Recovers on the HiFi position as soon as the VHF stop emitting a signal. 3 positions: O position = HI / FI only, V position = VHF only, Has position = AUTOMATIC (pass from one to another). Technical Characteristics: • Power Supply: 12 volts • Consumption: 15 my one O position / 70 my in VHF Reception • Temperature: 0 ° C to 65 ° C • Dimensions: 120 x 56 x 31 mm • Weight: 120 g • Fixation: 2 screws