Arrow Fastener T59 5/16" Width 1/4" L Black 18 Ga Pack of 300 Insulated Staples Pack of 2 Packaging may vary. The T59 insulation standard for professional telecom installers, is made to secure low voltage wires and communication cables without damaging sensitive communication wires. Suitable for computer, CAT5 / CAT6, RG6 / RG9, COAX, phone cable These staples work on any data, video, or communication wire up to 5/16". Insulators are clear or black to match the wires that are fixed.