EasyAlarms Wireless Weatherproof Garden, Shed, Driveway, Garage, Outbuilding Burglar Security Alarm PIR WEATHERPROOF WIRELESS SENSOR & RECEIVER UNIT WIRELESS RF TRANSMISSION UP TO 400 FEET/ 121 METRES PIR SENSOR WILL DETECT MOTION AND TRIGGER THE RECEIVER TO TURN ON ALARM OR CHIME SOUND HI/LOW SWITCH, ALARM/CHIME/OFF SELECT SWITCH PIR WIRELESS SENSOR USES 9V BATTERY, not supplied