The Motion Alert Alarm uses a passive infrared system which detects motion in any selected area. The motion alert alarm mounts easily (vertically or horizontally) near any entry area and is battery operated which eliminates any need for wiring. The motion alert alarm can be coded with a personal safety security code and can be set to utilize a two-tone entry chime instead of the alarm sound. Mounting screws and AC connector included. Requires one 9 Volt battery. (not included) Dimensions are 3" x 5.5" x 2".