Ideal for wireless extension of your doorbell: Place active transmitters next to the existing doorbell. As soon as this rings, the receiver connected via radio is activated. 8 selectable ring tones Automatic learning code encoding Expandable with up to 3 additional transmitters and multiple additional receivers. Can be used as radio extension of cabled bell-systems. Radio range up to 200 m outdoors.Transmitter:Ideal for wireless extension of existing doorbell. Microphone sensitivity can be adjusted continuously. Radio range depends on the receiver used - up to 200 m in free field. Also for telephones! Control lights for batteries and transmission function.ReceiverBattery-operated radio doorbell. Additional visual indication of ring tone with blue LEDs - Ideal in loud environment or for the hearing impaired. Function button for: Visual + audible message · Acoustic message only · Only visual message. Adjustable volume (max. 80 dB/m).This text is machine translated.