Wireless Battery-operated Doorbell 48 Sounds 100m Opera

technical data:general:transmission type: wirelessrange in open area: 100mcolor: blackpossibility of expansion with additional transmitters: yesreceiver:receiver power supply voltage: 3 x aaareceiver power supply type: batterybattery included: nonumber of ringtones: 36ring volume level (db): 50-90volume adjustment: yesoptical signaling: noreceiver dimensions (width / height / depth [mm]): 78 / 86 / 34transmitter:transmitter power supply voltage: 1 x 23apower supply type transmitter: battery-poweredbatteries included (transmitter): yesip protection rating: ip44transmitter dimensions (width / height / depth [mm]): 40 / 86 / 20wireless doorbell range in open area up to 100 m waterproof doorbell button radio transmission (frequency 433mhz) adjustable ringtone volume sound level 50–90 db 36 polyphonic ringtones to choose from the number of cooperating transmitters can be increased as needed learning system (automatic login) does not require doorbell installation.**photos are for illustrative purposes only.