Photocell set for mounting in the clear width or rails. Works with all major operator brands/control units. This transmitter and receiver have a cable length of 15000mm, waterproof IP 64, 10-30V DC. Maximal range of the photocells is 8 meter. Inside diameter is 12 mm. Receiver RX is grey and transmitter TX is black. Connection: With the transmitter, the black and brown wire to the positive, blue on the minus. With the receiver, brown wire to the positive, blue to the minus and yellow is switch wire.