Spring loaded ball bearing on head holds socket securely. This set of socket adapter can change your hand socket set into a driven socket set. These impact ready adapters are rated for the most demanding of applications (2000 in/lb of torque). Chrome vanadium steel is suitable for heavy duty impact drivers. There are 3 sizes of socket adapter hex shank. It is suitable for quick change 1/4" chuck systems or directly into drill chuck. This set is perfect for your impact driver or drill, and allows you to replace your ratchet with a power tool. Item Name: Socket Adapter Hex Shank Material:Chrome Vanadium Steel Size Details: 1/4"*1/4"*50mm--1/4 "shank can be converted into 6.35 mm square. 3/8"*1/4"*50mm--1/4 "shank can be converted into 9.53 mm square. 1/2"*1/4"*50mm--1/4 "shank can be converted into 12.7 mm square. Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 X Socket Adapter Hex Shank (3Pcs)