The Craftsman 21 mm X 1/2 in. drive Metric 12 Point Deep Socket is a high-quality hand tool designed for automotive use. Made by the reputable brand Craftsman, this single item socket features a standard size of 21mm and a 12 point drive type for easy and precise tightening and loosening of nuts and bolts. With a lifetime warranty, this durable and reliable socket is a valuable addition to any mechanic’s tool collection.