Corning Cable Systems Zipcord Cable utilizes two 900 µm TBII buffered fibers surrounded by aramid yarn strength members with a flame-retardant jacket. This cable meets the application requirements of the National Electrical Code (NEC Article 770) and is listed as Type OFNR and CSA FT-4. Zipcord cable is ideal for interconnect applications and is available with approval for TEMPEST applications.