Wirele Doorbell Self Powered Door Bell No Battery Required Easy Installation 51 Ring Tones Volume Adjustable High-quality wirele doorbells, with CE and RoHS and other certificates. Latest self-powered technology that does Not require any battery. Waterproof IP44. Don't worry about extended use in heavy rain. Remote control range up to 150m in open space. When chime working indoor, it will be affected by the thickne and quantity of the wall, and the distance will be about 20-80 meters. Meet the needs of most residential and high-rise buildings. Upgraded with a new chip, it will not affect each other's signals. Newest Chips, Advanced Technology Advanced signal proceor, super-sensing antenna. The digital signal circuit is more resistant to interference. Self Powered, No Battery Required Button does not need to install battery. When preed, kinetic energy is converted into electrical energy. Stronger Signal ,Further Distance Signal is stronger, enhanced wall penetration and propagation distance. Multi Ringtones optinal and Volume Adjustable 51 Ringtones with adjustable volume, good sound quality Waterproof , working outside in any weather Easy Installation No wiring required; no tools required. No need to make holes or damage anything. Package Included Button x1 Receiver x1 Manual x1 Acceory pack x1