The Safe T Alert 40 Series Professional Propane/LP Gas Alarm is designed for the rugged RV environment and is ideal for Class A motor homes, Class B van campers, Class C mini-motor homes, travel trailers, fifth wheels, trucks and folding campers. It features advanced technology with an Alarm Mute button that silences the alarm when the RV is ventilated and rapid recovery sensor that resets when silenced or reactivates if dangerous levels of propane remain. Easy 12 Volt installation means there will be no missing or dead batteries to replace. Meets RVIA/NFPA requirements. Listed to UL 1484 RV. Safe-T-Alert 30 Series Slim Line LP Gas Alarm, Flush Mount. UL listed for RV use. The Slim Line surface mount case eliminates cutouts. A dual Test and Mute switch checks the alarm's functions and can silence the audible alarm for two minutes.Features Color - Black Test/Reset Button - Mute function. Tests all detector functions with one touch.