A zipper, zip, or zip fastener, is a commonly used device for binding the edges of an opening of fabric or other flexible material, as on a garment or a bag. It is used in clothing (e.g., jackets and jeans), luggage and other bags, sporting goods, camping gear (e.g. tents and sleeping bags), and other items. Whitcomb L. Judson was an American mechanical engineer from Chicago who was the first to invent, conceive of the idea, and to construct a workable zipper. The method, still in use today, is based on interlocking teeth. Initially it was called the “hookless fastener” and was later redesigned to become more reliable.