16 polyphonic music wireless doorbell; infrared motion sensors; can use as a doorbell or alarm; receiver using a common flat or round plug inserted; open areas to accept distance greater than 100 meters; sensor sensing range of 6-8 meters; Inductor 3 gold 1.5VAAA batteries (not included); 32 optional wireless doorbell exchange

Power Source: AC
Power supply voltage: 220v (V)
Ringtones: 32 computer selections / 16 polyphonic
Scope: home， building， engineering， hotel
Packaging: color card
Packing list: a door machine， an indoor unit
Product size: 146 * 214mm
Product Weight: 0.17kg

Instructions: Use strictly in accordance with the installation requirements before installation
Note: Please try to use high-quality alkaline batteries

Product Dimensions: 15 x 14 x 4 cm