This is a 30m BNC (male) to BNC (male) black coaxial simplex PVC copper patch cable. A coaxial cable is used for carrying lower-frequency signals, in which the dimensions of the cable are controlled to give the precise, constant conductor spacing which is needed for it to function efficiently as a transmission line. This PVC jacketed cable is best suited for LANs or SANs, and is recommended for connection between fiber patch panels, hubs, switches, media converters and routers. A simplex cable is a single strand of fiber that works best with bi-directional transceivers as well as other single-transmitting devices.