Portable Motion Detector Alarm/Chime Triggers a piercing 90dB alarm or more subtle chime if someone enters or passes by LED low-battery indicator; requires one 9V battery (Not Included) 100 Detection angle; 30 feet (9.1m) at 68F (20C) detection range Compact design works with virtually any door; bracket included; no wiring needed Delay feature gives you 15 seconds to enter or leave before alarm goes off