... explosion, fire, suffocation accidents malignant. · Suit small family use gas safety products, and applicable to NG, LPG, and MG.· ... Can effectively avoid gas leak caused by the explosion, fire, suffocation accidents malignant.· ... Can directly control fan and cut-off valve.Specifications· Detect principle:semiconductor· Detected gasNG,LPG,MG· alarm concentration:NG:4% ...