Features: *Wireless smart voice doorbell to talk to visitors via two-way voice intercom to let you know who is visiting your house and talk to them to let them know I'm coming, please wait.* 1 receiver and 1 button to talk between receiver and button via wide range wireless connection (outdoor clock: 200m, indoor clock: 5 - 50m, no obstacle), stable transmission signal to make speech clear.*The receiver supports rechargeable batteries and the transmitter supports 3 alkaline batteries for up to 4 months (3*transmitter alkaline batteries not included)* It is widely used in office and home, do you know who is outside, is it convenient?It takes longer to open the door at birth, which is very convenient.With 15 different ringtones and 3 adjustable volume levels.* Easy to install and use, visitor presses the outdoor doorbell, after the bell rings, you need to press the button on the receiver once to connect, then hold it to speak, release when finished.