The most common cable tie consists of a flexible nylon tape with an integrated gear rack, and on one end a ratchet within a small open case. Once the pointed tip of the cable tie has been pulled through the case and past the ratchet, it is prevented from being pulled back; the resulting loop may only be pulled tighter. This allows several cables to be bound together into a cable bundle and/or to form a cable tree.
A cable tie tensioning device or tool may be used to apply a cable tie with a specific degree of tension. The tool may cut off the extra tail flush with the head in order to avoid a sharp edge which might otherwise cause injury