Please use 9-15V power supply (1A or above) Induction method: infrared sensor triggered 3 modes: Voice Alarm Music,at "Voice" mode: Human voice,dingdong,ninhao, ;at "Alarm"mode: keeps you aware of intruders;at "Music" mode: just as a doorbell,with 32 music to welcome your guests Power supply: DC 9-15V adaptor(not included) or 3 x AAA battery(battery not included) Detection Angle: Horizontal Angle of 110 degrees, vertical Angle of 15 degrees, Manufacturer: Mcnhbdgg