Audio cables are electrical cables or wires with specific characteristics to transmit audio signals. There are many different products. Coaxial cables consist of two cylindrical conductors that are separated by a dielectric, but which have a common axis. RG6 and RG11 audio cables are inexpensive, unbalanced coaxial cables which consist of a central, metallic core surrounded by a layer of insulating material. RG6 audio cables are used in many cable television and satellite applications. RG11 cables are used as thick Ethernet (thicknet) cabling. Fiber optic cables are relatively expensive and difficult to install, but provide near-infinite bandwidth and near-perfect immunity to noise. Audio cables also include closed circuit television (CCTV) cables, community antenna television (CATV) cables, general-purpose audio cables, multi-signal or composite cables, and power limited tray cables (PLTC). For each type of audio cable, performance specifications include the number of conductors, nominal outer diameter, impedance, and operating temperature.