The Black Cable Tie, also known as a zip tie, is a type of fastener, designed for bunching electric cables or wires together. The cable tie helps to organize cables and wires, but is also used in a wide variety of applications.The Fastener Factory sells the nylon cable tie which consists of a tape section with triangular teeth that slope in one direction. The head of the cable tie has a slot with a flexible pawl that irreversibly rides up the slope of these teeth when the tape is inserted. The pawl engages the backside of these teeth to stop removal of the tape.