Feature:  Infrared motion sensor: Imported infrared motion sensor with 4-5m control range, much more accurate.  With 38 chord music and 3 volumes control: You can adjust it according to your condition.  Wire-free installation: Never worry about the disorderly wire affecting the appearance of your room.  Exquisite design: Simple appearance and comfortable luster, fit all kinds of decorative style well.  Ideal for hotel, home, store, office, villa and anywhere you want to be alerted to motion.     Specifications:  Color: White.  Induction angle: 120°.  Sensing range: 4-5m.  Shell material: Plastic.  Power supply: DC5V/3 x AAA Battery(NOT Included).  Application: Hotel, home, store, office, supermarket, etc.  Button function:  1) Three gear volume adjustment.  2) ON/OFF.  3) Mode: Mode1--38 chord music switching; mode 2--fixed "welcome" voice; mode 3--fixed alarm tone.     Package Included:  1 x Wireless Door Bell.  1 x Accessories Bag.  1 x User Manual