The Ko-ken RS4400W/8 1/2" Square Drive Socket Set is a specialized Whitworth socket collection featuring eight precision-engineered 6-point sockets, including sizes 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", and 5/8", all mounted on a durable 250mm rail for organized storage and easy access. Designed specifically for use with Whitworth fasteners, this socket set provides optimal torque and a secure grip, ensuring efficient performance in various applications. The robust construction of the Ko-ken RS4400W/8 Socket Set makes it an essential tool for professionals and enthusiasts who require reliability and precision in their work.