Propane has become the fuel of choice for cooking and heating. Highly BTU-efficient and readily available, propane is becoming more and more a part of power boating, sailing and camping. Propane is heavier than air and can settle below deck and in the bilge where it can be detonated by an engine start-up or electrical spark of any kind. Fireboy-Xintex® Propane Fume Detectors will alarm when fumes reach 18-20% LEL (Lower Explosive Limit). The Fireboy-Xintex® line of propane products includes everything you need for outfitting a complete and safe propane system.