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. 52 Beautiful Chimes and Melodies: Offers 52 classic melody chimes with adjustable volume control and diverse selection to meet your needs. 4 adjustable volume levels from 0dB to 90dB, 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 of notification (a great feature for the hearing impaired). IP44 Waterproof: IP44 waterproof transmitter design, made of ABS, non-toxic, safe and recyclable, can work at temperatures between -20℃ and 65℃, and withstand various severe weather conditions, sun, rain, snow, frost etc. Widely used for home, office, hotel, villa, hospital, study, apartment, school