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.

• This is a Wireless Door Bell, but No more battery needed or Worry battery runs out ! By pressing the push button, it converts kinetic energy into an electrical signal to ring your wireless doorbells. So no more worrying your push button runs out of batteries and no more hassling in buying awkward weird batteries to run your push button. You will always be able to hear your doorbells ring!
• Do not need any battery or power line to charge the transmitter, and it transforms its own mechanical energy to electrical energy by pressing the button on it. Do not need any wire for installation, easy and convenient to use
• Transmitter can be used in both high-temperature and low-temperature environment: from -40 to 60 Celsius degree. Transmitter is made of ASA plastic, durable to use.
• Waterproof transmitter: can stand against heavy rain. Receiver is made of ABS plastic, inflaming retarding and environmental protection.
• Long wireless transmission distance: up to 70 meters (no obstacles, in open field). Easy operation: the transmitter can be fixed on the wall by screws or adhesive pad and the receiver can be inserted to the power socket. 25 different polyphony ring tones for your choice.

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 !