Physen Diamond Wireless Doorbell Sound Features 2 Waterproof Doorbell Pushbuttons and 1 Doorbell Chime, Doorbell kit with 52 Melodies and 500 Feet Operation Rang(Black) Doorbell with diamond seamlessly appearance shows you high-end simple and elegant visual effect;ABS material ensures longer life This doorbell push button features unique waterproof technology instead of most non water-proof buttons in the market;moreover touching button enchance your using experience Operation range of this doorbell kit up to 500 feet (1000 feet in open area),for longer operation rang pls do not mount the push button on metal material 4 levels volume adjustable (from 25db to 85db), 52 (16 chord) elegant chimes allow you to change the tune with your mood as well as set tune to a specific receiver chime No wire needed,just plug the receiver in the wall, and mount the wireless transmitter using the supplied double sided tape or mounting screws and that's it, CE, FCC, RoHS certified