2PCS Home Low Power Mobile Intercom Doorbell, Long Distance Wireless Voice Call, Elderly Pager, High Voice Home mobile intercom doorbell, long-distance wireless voice call feature: *Wireless smart voice doorbell, talk with visitors through two-way voice intercom, let you know who is visiting your home and talk to them and let them know that I am coming, please wait. *1 receiver and 1 button, the receiver and the button communicate in a wide range through wireless connection (outdoor bell: 200m indoor bell: 5-50m without any obstacles), the transmission signal is stable, and the voice is clear. *The receiver supports rechargeable batteries, and the transmitter supports 4*AAA batteries, which can last for nearly 4 months (excluding the transmitter 4*AAA batteries). *Widely used in offices and homes. It is very practical to understand the people outside and facilitate the elders who need more time to open the door. *Easy to install and use. Visitors press the outside doorbell. After the bell rings, press the button on the handset to connect, then press and hold to speak, and release it when finished. Specification: Indoor unit input voltage: 5V 1A Outdoor unit power supply: 4*AAA batteries (not included) Indoor unit power supply: built-in lithium battery (included) Wireless frequency: 467.6375MHz Transmission distance: outdoor bell: 200m indoor bell: 5-50m (barrier-free) Waterproof: no waterproof function Outdoor unit working time: 4 months (close to) Indoor unit working time: 48 hours (entry) Color: golden Material: Plastic + ABS Working temperature: -20? to 55? Packing size: Approach.16.2*11.8*2.4cm/6.38*4.65*0.94in Package weight: Approach.155g/5.47oz