[. . . ] Transmitter and Receiver communicate each other by having the same channels. Receiver REC 100 HF has been preset its System Channel at I and unit channel at 9 before it's ex-factory. [. . . ] Keep Receiver REC 100 HF being located from surrounding conductive device, such as aluminum reinforced UPVC window and door, metallic plate, and electric cables, at least one meter away. During installation do not change or move antenna inside Receiver REC 100 HF. During installation, keep electric cable form nearing to antenna that would cause radio waves interference and thus affect the signal reception from the combining transmitter. Avoid testing Receiver REC 100 HF and the combining transmitter by holding in hands, do install them on the wall or ceiling since the human body is the kind of antenna that would cause interference to wirefree device. Fix the bottom case tightly with screws on the selected position (See Fig. Before wiring, break the reserved knock-holes that allow wires pass through. â· After wiring, make sure all wires are correctly connected. In accordance with your existing wiring layout, choose wires either pass through the inside wall or through the outside wall (See Fig. Set channel, if its is necessary, then cover the front case and fasten it with four screws (See Fig. Through inside wall Through outside wall Switch opened (is controlled by transmitter) Switch closed (is not controlled by transmitter) Transmitter and Receiver interwork by means of sending ON or OFF signal from a Transmitter to its combining Receiver and correspondingly a Receiver receives the signal from the combining Transmitter and reacts to the signal received. [. . . ] Theben HF products are allowed to sell to all EU IRL CH A and EFTA countries. The receiver complies with essential safety and radio frequency with CE (LVD & EMC) and R & TTE directives. [. . . ]