Marine Scene, Porthcawl stock the Pilot 12v Gas Alarms. We have two models on offer, namely the Pilot Mini Gas Alarm and the Pilot Dual Gas Alarm. Both of these models are powered from a 12v battery. They operate by sensing and providing a warning alarm for concentrations of LPG, Butane and Propane in the atmosphere. Although the units are not calibrated for diesel and petrol vapour in the air, but these can be detected at higher concentrations.