house kitchen wireless interlinked smoke alarms optical smoke alarm More detail: https://www.firealarmfactory.com/interlinked-smoke-alarms.html more...
model no sr-820phw-ac operating voltage ac110/220v(9v backup battery) interconnection install within the radius of 200 m hush function yes code form 2262 sending frequency 433mhz radio distance 200 m(open area) sensitivity 2.06%ft±1.3%ft sound level 85db/3m installation wall or ceiling mounted workin more...