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 convenient, energy-saving and practical than the old one. IP44 Waterproof & Temperature Display: IP44 waterproof design of the transmitter, made of ABS, non-toxic, safe and recyclable, can work 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 & Melodies: Offers 38 classic melody chimes with adjustable volume control and diverse selection to meet your needs. 4 adjustable volume levels from 0dB to 100dB, which is loud enough for the elderly to hear; enjoy pleasant melodies every time someone rings your doorbell. The LED indicator gives you a visual form