[Simple Installation & Expansion!] Secure this outdoor doorbell chime to your door or wall with the included screws for ultimate security. The wireless intercom doorbell is expandable, so you can extend nearly any indoor or outdoor system, even to a set of 2 transmitters and receivers each! | [Long Range & Easy Sound Adjustments] This wireless doorbell transmits at a distance of up to 1/2 Mile! Customize your doorbell with 20 kinds of chimes and 3 volume levels! | [Wuloo Brand] Wuloo are specialized in FM / ASK /FSK wireless techology for more than 20 years. Package equiped with quick start guide and detailed manual. | [Anti-interference & Multifunctional] This doorbell doubles as an FM wireless intercom doorbell that won’t be affected by WiFi disruptions! It also won’t interfere with your other smart devices. Buy two receivers and use as a set of walkie-talkies, or use the mute mode on the indoor intercomunicador to turn off the unit when you want silence. | [IPX55 Waterproof and Built-in Rechargeable Battery] The Wuloo intercom doorbell is waterproof even in bad weather conditions like snow and rainstorms. Features low power consumption, built-in 2000mA battery, and an included charging base! Full battery lasts 4-6 months for the transmitter, and indoor machine lasts 1-2 days on a full charge.