Latest PUSH-RF technology & battery-free This wireless doorbell is self-sufficient, does not require cables or batteries, protects the environment and saves your money. When the transmitter is pressed, it generates electricity by itself and sends a stable signal to the receiver. Never again worry about damaging the wall or the doorbell when changing the battery38 ring tones and 4 volume levels Our wireless stereo loudspeaker for the doorbell delivers a rich and clear sound. It offers a wide selection of 38 ring tones and 4 volume levels (including muting) to suit your personal taste. Press and hold the volume button to return to the first ring (dingdong). With a memory function, the radio bell remembers your last settings after a power failure.NO Crosstalk & False Alarms This cordless doorbell has strong penetration and anti-interference. The area for multiple obstacles is up to 152 m (500 feet) and in open areas it is up to 305 m (1000 feet). It doesn't interfere with other equipment in your home or those of your neighbors, and ensures that you never miss a visitor, even if you are a few rooms away or on a different floor.Quality assurance and satisfied service Our cordless trgong is dustproof and IP44 waterproof and can withstand various harsh weather conditions. According to our test, the push button can achieve a maximum service life of 20 years and up to 150,000 clicks. We also offer a 2 year guarantee plus 60 days satisfaction or right of return. If you have any problems with our products, please feel free to contact us for a satisfactory solution.