KEWAYO Wireless Doorbell with 1 Remote Button and 2 Plugin Receivers Operating at over 1000 Feet Range with 36 Melody Chimes, No Batteries Required for Receivers Waterproof design of transmitter for rain. 36 different ring tones, 4 levels volume are adjusted. Remote control distance can be up to 1000 feet in open and interference-free environment. Ultra low power design, sustainable use. Includes 2 plugin receiver unit and 1 remote transmitter button, double sided sticker, screws, and built-in battery in remote transmitter.