A swift is a tool used to hold a hank of yarn while it is being wound off (uncoiled from the hank and rewound in a form usable for knitting or crochet).[1] It has an adjustable diameter so that it can hold hanks of many sizes, and rotates around a central rod.[1][2] Developed in the United States,[3] they are generally made out of wood or metal, though other materials may also be used. In the 18th and 19th centuries, swifts were sometimes made of whale ivory[3] and they are now sought-after antiques. Swifts are not used very much in the textile industry but are used more by knitters and crocheters who buy their yarn in hank form. The swift allows for easy balling without the yarn getting tangled and knotted.