These gas detectors have the capability to control two sensors which detect both LPG and petrol, with visual and audible alarms. Features include test switch to check operation of sensors as well as outputs for external audible alarm and bilge blower operation. Units are supplied standard with one sensor with five metre lead. The 113122 detector also has an LPG shut off feature that shuts off gas supply when in alarm mode. An on/off button is also incorporated to control gas supply remotely. This is achieved through a pulse and hold output that is connected to the 113137/113138 LPG shut off solenoid which is purchased separately. The pulse and hold circuitry incorporated in the 113122 detector pulls the valve in at 12 volts and then, once energised, will step down the voltage whilst still holding the valve open. This reduces power consumption and heat generation while the gas is on.