When you want to have a talk with the other, press down the push button and bell of his or her set will ring no matter whether you take up your handset or not.While talking, please speak into the micro phone.When you talk is over,put back the handset,see to it that the pilot light is off,or else the talkback set is still in working condition and continue to consume electric power.Our talkbacks are convenient to connect by means of twin conductor in common use, while connecting, please pay attention to the colour of the two different conductors.The effective talkback distance is 3 kilometers(9842ft), with wire resistance less than 60 ohms.The ring sounds level can’t be selected.
Feature:Intercom doorphone for double roomsThe pair units needed to be wired to each otherOperation distance 200m 2-line connected (3.3ft cable come with this parcel)Energy saving, no currentConsumption while not work

For point to point communication.Secretary to boss, gateman to boss, room to room. Up to a distance of 200meters clear communication? with energy saving and no current consumption while not work.?Intercom DoorPhone for double roomsOperation distance 200m 2-line connectedDIY easy to install.?Ring sound level >70dB