-powered Wireless Doorbell wireless doorbell kit includes one transmitter and one receiver, the transmetter don't need powered, it generates power by pressing it then it will the reveiver, ecofriendly and energy saving compared to traditional wireless door bells. doorbell is for a department, flat, lodging house...Wireless Doorbell up to 400 ft/120m Range bell ring range is up to 400 ft/120m, and loud and clear enough to hear the bell in every corner of your house. the bell is ringing, the LED indicator will be on too.38 Melodies to ChooseInside of the front doorbell, there are 38 melodies to choose from, and 3 sound volumes, you can choose whatever you want. Note: if you pull out the receiver, and you need to reset the song.Easy InstallationTwo ways to install the press button. is to use the srcews and fix the plate and hook the press button on the plate. An is to use the double-sided tape to fix the press button(no plate needed). Choose based on your need. proof Wireless DoorbellThe front door bell is made of high quality waterproof and dusproof material, ensure the bellring works effeciently. Note: pls don't expose the transmitter directly to the rain and the sun and keep it away from the metal.