Wireless Welcome Doorbell Guest Welcome Chime Alarm PIR Motion Sensor For Shop Entry Security Doorbell Infrared Detector|Doorbell(white) Item specifications: * Power supply : DC 9-15V (battery not included) * Detection range: 4-8 m * Volume: 4 levels adjustable (Can't adjust volume at alarm mode) * Induction method : infrared sensor triggered * 3 modes: Voice Alarm Music,at "Voice" mode: Human voice,dingdong,ninhao,huan ying guang ling;at "Alarm"mode: keeps you aware of intruders;at "Music" mode: just as a doorbell,with 32 music to welcome your guests * Ambient temperature/humidity :. -10 -40 5% -95% RH * Detection Angle: Horizontal Angle of 110 degrees, vertical Angle of 15 degrees * The main function: Automatic body sensing , ultra-long , wide-angle detection. Adjustable direction (with stand). Host built-in speakers, alarm loudness of 75-95 db * Installation : No need professional personnel, easy to install yourself * Installation height: 1.5m-2.5m * Music: 32 music and vocals optional * Size: Height 7.5cm Width 8cm , thickness 4.5 cm (with base - base can be flat or fixed on top) * Battery: 3 x AAA batteries (batteries are not included)