The Ko-ken RS4405W/8 1/2" Square Drive Socket Set is a versatile collection designed specifically for Whitworth fasteners. This set includes eight 12-point sockets ranging from 3/16" to 5/8", organized on a compact 250mm rail for convenient storage and access. The included socket sizes are 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", and 5/8". The 12-point design ensures a secure grip and improved torque application, making it ideal for various applications in mechanical and automotive work. With the practical rail system, your tools will always be organized and ready for any task.