General Information Type of transmission: wireless Range in the open area: 100m Colour: gray Possibility of extension by an additional transmitters: yes Other features: possibility of a power supply from a 5V DC power supply unit Receiver Power supply of the receiver: 3 x AA Type of power supply of the receiver: via battery Battery included: no Number of ringtones: 32 Doorbell volume (db): 50-80 Volume adjustment: yes Optical indication: yes Dimensions of the receiver (width x height x depth [mm]): 82 / 82 / 36 Transmitter Power supply of the transmitter: 1 × 23A Type of power supply of the transmitter: via battery Battery included (transmitter): yes Protection rating: IP44 Dimensions of the transmitter (width x height x depth [mm]): 42 / 81,5 / 27