The typical Colour Cable Ties, which is often constructed of nylon, features a flexible tape part with teeth that engage with a pawl in the head to form a ratchet, allowing the Cable Tie to tighten and not come undone when the free end of the tape section is pulled. Some ties have a tab that may be depressed to release the ratchet, allowing the tie to be loosened or removed and reused. Stainless steel variants, some of which are coated with tough plastic, are suitable for outdoor applications and hazardous situations.