No Battery Required: Our wireless doorbell transmitter uses unique PUSH-RF technology. When you press the button, the kinetic energy is converted into an electrical signal that rings your doorbell wirelessly. No more worrying batteries. More practical, more energy-saving and more convenient than the old one. IP44 Waterproof & Temperature Display: IP44 rating Waterproof design of the transmitter, made of ABS, non-toxic, safe and recyclable, which can operate at temperatures between -20℃ and 65℃, and withstand various harsh weather conditions. LED temperature display screen, Celsius / Fahrenheit temperature appears when the receiver is not ringing, can be used as an indoor thermometer. 38 beautiful chimes and melodies: Offers 38 classic melodic chimes with adjustable volume control and diverse selection to suit your needs. 4 adjustable volume levels from 0dB to 100dB, which is loud enough for old people to hear; enjoy pleasant melodies whenever someone rings your doorbell. The LED indicator gives you a visual form of notification (a great feature for the hearing impaired). Long Wireless Range: With 150M / 500FT wireless range, 2 plug-in receivers included, won't interfere with other equipment in your home or your neighbors; ensures that you will never miss a visitor, even if you are a few rooms away or on another floor. Ideal for home, office, hotel, villa, hospital, office, apartment, school and other suitable fields.