1、Battery Free: Self powered wireless doorbell, one to one signal pairing, 2pcs transmitter and 2pcs receiver can be used for double door double deck house, can set a separate corresponding ring tone. 2、Nursing Pager: Not only a doorbell, but also a wireless caregiver pager, suitable for the elderly, patients, pregnant women, guarding your family members. 3、Waterproof Doorbell: Self generating doorbell has IP68 waterproof grade, can be used safely in rainy and foggy days, and prolong the service life of the doorbell. 4、Long Range: The doorbell supports long distance signal transmission of 150m/164yd in barrier free area, can wirelessly through the wall and has strong penetration power. 5、Loud Volume: Wireless doorbell has loud sound, solve the problem that the elderly can't hear. You can also set one button mute, will not disturb the patients, convenient for the elderly to use.