Ideal for wireless extension of your existing doorbell doorbell: active transmitter. As soon as this is, the connected receiver via radio is activated. 8 selectable ring tones. Automatic learning code encoding Can be extended with up to 3 additional transmitters and several additional receivers. As a wireless extension cable-based bell systems can be used. Radio range up to 200 m in free field.Transmitter:The sensitivity can be set continuously. Also works with phones. Control lights for battery and transmission function.ReceiverContinuously adjustable volume. Sound turned off, e.g. during night's rest. Optical ring display with light ring - 3 colors can be set. Battery indicator light.This text is machine translated.