No wiring required, plug and play. The transmitter button can be attached to any convenient place. The doorbell can be used directly by plugging it into the USB power port. No wiring is required and the wall is not damaged. 150 meters remote control distance covers the whole house. +17Dbm strong signal, straight line unobstructed remote control distance can reach about 150 meters, easily penetrate multiple concrete walls, and the whole house signal is easily covered. 30 music with multiple adjustable volume levels. Say goodbye to the simple "ding " sound. 30 built-in cool ringtones are available for selection. The volume can be adjusted in three levels to match the needs of different groups of people. This wireless remote control doorbell set adopts the main control chip programming. Multiple sets of doorbells are used in combination without serial code. It has the characteristics of low power consumption and small size. It is very useful in home doorbell bed calls or emergency calls for the elderly. Strong signal covers the whole house. Remote control Modulation mode: ASK Encoding format: EV1527 Operating frequency: 315/433.92 MHz Operating current: 20mA for transmission/0.1uA for standby Applicable battery: 2016*3 button battery Controller Operating voltage: DC5V/1A Operating current: 120mA Standby current: Less than 4.6mA Modulation mode: ASK Signal frequency: 315/433.92MHz Colour:White Material:ABS Package Contents: 1 * Doorbell 1 * Remote Control 1 * Chinese and English instruction manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.