Product Feature This smart wirele doorbell adopts advanced wirele transceiver technology, high-quality voice proceing technology, and its performance is stable and reliable. The doorbell, anti-theft, is welcome multi-purpose. Suitable for home, villa, shop, hotel and office, etc. Smart wirele doorbell When you pre the button,doorbell will receive the signal and you will hear the sweet tunes immediately. Infrared detecter welcome mode When the infrared detects a moving object will send a signal to the doorbell, the doorbell emits a welcome sound. Door sensor alarm mode Install the door sensor on the door or window. When someone pushes open the door and window, the doorbell receives the signal and will alarm. 150M long distance transmiion Long operating range can be up to 500ft(150m) in open space,great for large house including villas, apartment, offices, shops, warehouses, etc. 32 Songs &4 Level volumes adjustable 32 ringtones for your option,you can select regularly,and don't feel bored,avoid the same ring with the neighbors.The volume can be adjusted according to the different environment. Customize doorbell kit according your need One transmitter can pair with several(max 30) receivers, and one receiver can pair with several(max 30) transmitters. Easy to install Just plug the receiver into power socket and attach the transmitter on door, you don't even necearily have to make holes or damage anything.Just plug the receiver into power socket and attach the transmitter on door, you don't even necearily have to make holes or damage anything. Technical parametersTechnical parameter 1. Operating voltage: AC 100-220V2. Working current: <100 mA3. Wirele frequency: 433 MHz4. Operating temperature: -10 C-50 C5. Wirele distance: 150 meters (open space) Warm tips about battery 1.