Enables an additional signal to be transmitted down the unused pairs of Cat5e twisted-pair cable. Allows expansion of an existing system without the need to disrupt the cable infrastructure. Used in pairs, one at each end of the cabling. Provides for instant network expansion. Although sold individually, the units must be used in pairs, with a device at either end of the cabling. PLEASE NOTE These units must be used in pairs, with a device at either end of the existing cabling. They are not suitable for telephones off broadband connections. They Must be used with patch panels & faceplates only.