Kaito Wireless Doorbell No Battery Needed for both receiver and transmitter, Battery Free Door Chime with 25 Ring Tones, Waterproof, Synchronize and Work in Pairs, Easy Setup

This is a Doorbell likes no other, No battery needed, Big save on Money every year ! The push button has no battery inside, you do not need to replace the battery at all, it works with No extra Power, Just a push of button . This newly invented door Chime has changed the idea of using a door bell, what you need to do is plugging the Doorbell Receiver on to any power outlet in the house, and set the push button near your door, you are all set, and you start to use the door bell. Never worry about the batteries in the Button or the Bell, so simple and easy !

Working range for 70 meters with no block, from the Chime Box, you have 25 melodies to select. The built-in melodies are easy to select, just a push of button on the box.
Specifications:
Certificate: CE Color: white
Material: ASA & ABS plastic
Power supply: receiver: AC100-240V, 50~60Hz;
Transmitter: self-powered Ideal transmission distance (open field): 70 meter
Radio frequency: 433MHz
Sound level: 85dB (at 1m/ 3ft)
Power consumption: ＜200mw
Transmitter operating temperature: -40 to 60 Celsius degree Receiver operating temperature: -10 to 40 Celsius degree
Transmitter size: 8.7 * 4.5 * 3cm/ 3.4 * 1.7 * 1.2 inches
Transmitter weight: 75g/ 2.6oz
Receiver size: 8.5 * 7.7 * 2.7cm/ 3.3 * 3.0 * 1.0 inches
Receiver weight: 86g/ 3oz
Package size: 20 * 18 * 7.7cm/ 7.8 * 7.0 * 3.0 inches
Package weight: 222g/ 7.8oz

Please read reviews and learn how to synchronize and work in pairs, you can program them to work together, one button for more bells, Cool !