The Pilot dual gas alarm is powered directly by a 12V battery. It has two sensors and can be wired to other multiple units with gas sensors in other rooms. It will sense and give an alarm for LPG, butane and propane. The unit is not calibrated for diesel fumes and petrol vapour but these will be detected at higher concentrations. Sensors should be fitted as low as possible but must not get wet. -Two gas detection sensor on a 3.5 metre length of 3-core cable -Draws 178 milliamps at standby rising to 210 milliamps in the event of an alarm -Dimensions: 35mm x 65mmx 120mm.