... or recoveryBuilt-in Back-up battery in the wireless alarm system Technical Parameter:Operating Voltage: DC 12V ... Static Current: ≤20mA Alarm Current: ≤400mA Wireless Receiving Frequency: 433MHzAnti-interference: 1V/m frequency:20-1000 ... the Wireless Alarm System Kit,Siren,Metal Remote Control,Wireless Door Sensor,Wireless Panic Button,Wireless Smoke Alarm,Wireless PIR Detector,Wireless Outdoor ...