The Optex BX-80N wired motion detector starts your security BEFORE burglars get inside. This attractive and low profile outdoor PIR detects up to 40' on each side, creating an 80'x 3' detection pattern. The Optex BX-80N suits almost all outdoor applications because it combines two PIRs, creating extra high immunity against false alarms caused by small animals, cars, and other outdoor disturbances. A selectable piezo buzzer can alert intruders and also serves as a convenient walk test indicator.