X-Sense Wireless Interconnected Smoke Detector Fire Alarm With Over 820 Feet Transmission Range, Xs01-Wr Link+

XS01-WR mini interconnected smoke detector with durable 10 years replaceable battery and advanced photoelectric sensor. When one alarm activates, all interlinked smoke alarms will sound; wireless technology with over 820 ft (250 m) transmission range (in open air) uses radio frequency to both transmit and receive messages concerning fire hazards in the home, giving you every extra life-saving second available to escape.