Brand new, a gift. It seems to be a doorbell, but I don't know how to use it. Infrared motion sensor smart wireless doorbell Main features: Infrared detector, can be used day or night 32 music options 4 volume control levels Battery and power supply Power supply: DC 9-15V (batteries not included) Detection range: 4-8 m Volume: 4 levels adjustable (volume cannot be adjusted in alarm mode) Sensing method: Infrared detector trigger Indicator light: Blue LED 3 modes: Voice alert music, "Voice" mode: human voice, dingdong, ninhao, fanyingguanlin; "Alert" mode: continues to recognize intruders; "Music" mode: like a doorbell, with 32 music tracks to welcome guests. Ambient temperature/humidity: -10 to -40 5% to 95% RH Detection angle: Horizontal angle 110 degrees, vertical angle 15 degrees Main functions: Automatic body sensing, wide-angle detection. Adjustable direction with stand, built-in host speaker. Alert volume 75.95 dh Installation height: 1.5m-2.5m Music: 32 music and vocal options. Size: Height 7.5cm, width 8cm, thickness 4.5cm (with base - base can be flat or fixed on top) Battery: 3 x AAA batteries (batteries not included) (alkaline batteries are recommended)