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 practical 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 receiver is not ringing, can be used as indoor thermometer.38 Beautiful Chimes and Melodies: Offers 38 classic melodic chimes with control adjustable volume and a diverse selection to meet 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 not with other equipment in your home or those of your neighbours; 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.Easy to Use: Convenient and easy to use design for better user experience. Just tear off the film on the transmitter and stick it next to your door. then plug the receivers into power outlets.