SMAGREHO Wireless Door Ring Bell Kit with 1 Remote Button and 2 Plug in Receivers 1 transmitter buttons triggers 2 chime unit, and The chime unit can be configured to ring with different melody/ringtone for both transmitters(Transmission range about 656-984ft outdoor and 656ft indoor) 36 chords Options. Built-in 4 levels of adjustable volume from 20db - 80db This doorbell is easy to installation, Plug-in receiver with 2-Pin US plug is suitable for an electrical outlet (AC), transmitter powered by one 12V/23A batteries, the enclosed double-sided adhesive convenience to paste on the wall Ideal for home, large office, shop and building of multi-floor etc. It can contact both areas to ring from someone pressing a single transmitter button. Attractive design and beautiful LED light color, makes you door look great