Self generation doorbell wirele home smart electronic remote control long distance no battery cordle doorbell Self power generation wirele doorbell,integration with 45songs, adopts advanced wirele transceiver technology and high-quality voice proceing technology. Wirele doorbell can be applied to apartment, villa,shop, hotel,home, office building,meeting room ect . 1. 45available tones 2.5 adjustable volume levels (including mute) 3. Memory function (when the doorbell receiver power on, the tone stays the same with the one being set last time) 4.Dazzling and colorful indicator light Self power generation No need battery, pre button and Kinetic energy turn into electrical energy . Ordinary doorbell was average changed a battery once a month , Every year need 12 batteries, one battery costs 1 dollar, You can save lots of money and batteriesevery year. Colorful light flashing with tones Doorbell Receiver flashing along with playing tones, easy to remind people there is someone coming. light is about 0.3W, only 1-3 kWh a year 45available tones 45tones for your option,you can select regularly,and don't feel bored.Avoid the same ring with the neighbors. 5 adjustable volume level After a busy working day and want a relax sleeping time ,youcan adjust it to mute.while the maximum volume can up to 100dB. Long distance transmiion Long operating range can be up to 500-700ft(150m-200m) in open space, great for large house including villas, apartment, offices, shops, warehouses, etc. Easy installation Just plug the receiver into power socket and attach the transmitter on door, you don't even necearily have to make holes or damage anything. Emergency call function There are two methods to learn bell button, one for doorbell function,the other is for emergency call function.you can selected a certain tone as emergency calling tone.It is very useful for old people andPregnant women . Power supply :AC 100~240V 50-60Hz Standby currents:< 3mA (220V AC) Working currents:<11mA (220V AC) Frequency:433MHz Receiving distance:200m(open area)