Wireless Dingdong Doorbell Self-powered 28 Ringtones 4 Levels Volumes Optional Long Distance No Battery Required 1 Transmitter + 2 Receiver,Black

Features:  *Self-powered doorbell with full-digital frequency modulation technology,no string code.  *With the strong points:ultra low power design,power saving,ultra long distance remote control, stable signal and strong penetration.  *The indoor receiver is equipped with 28 chord tones and 4 levels of volumes for your choice.  *Outdoor transmitter does not need batteries.No batteries!!built-in energy power generation module for transmitter,so you will never worry about battery replacement and power running out.  *Simple appearance design and elegant, unique style,which will make your house more fashionable.      Specifications:  Receiver Voltage:AC110V-240V  Transmitter:No battery required  Operating frequency:433.92MHz±200KHz  Volume:25-110dB(4-step volume adjustable)  Ringtones:28 options  Transmission range:20-50m(depending on the environment)  Power consumption:0.1W  Color:Black  Material:ABS  Quantity:2*Receiver&1*Transmitter  Receiver operating temperature:-10?~55?  Transmitter operating temperature:-20?~65?  Transmitter size:7.5*4.5*2cm  Receiver size:9.2*6*3cm      Package Information:  Package Size: Approach.14*11*8cm/5.51*4.33*3.15in     Package Weight: Approach.250g/8.82oz      Package List:  2*EU Receiver  1*Transmitter  1* Tape  1*User Manual(English)