Wire channel accessory kit. Contains the following items : 4-wire channel clips to mount wire channel to flat surface, 5-wire channel straps to mount wire channel to uneven surfaces, 4 couplings to join and support connecting lengths of wire channel, 8 bushings to slip into open ends of wire channel to protect wires and 4 connecting covers to conceal any open gaps between lengths of wire channel. UL (Underwriter’s Laboratories) listed. For use with NM wire. (B Series System).