Motion sensor has 140 to 40 deg. detection zone. Activation switch allows chime or alarm to sound. Uses 4 "AA" alkaline batteries (not included). Door chime plays 8 sounds: Dong, Ding Dong, Westminster Chime, Star Spangled Banner, Hail Hail the Gangs All Here, Jingle Bells, Auld Lang Syne, and Dixie.