A zip tie is a fastener often made of durable nylon. Most often, they are used to organize cords, cables, and attaching items together. Often, zip ties are very secure, making it difficult for movement of an item. In relation to the bondage community, zip ties are sometimes used to restrain wrists, ankles, and inhibit mobility. Their extreme durability makes it hard for zip ties to become undone without the use of scissors or other tools.