The Universal Grip is a cleverly designed socket that has steel rods inside that can instantly grip any shape. It can be used on a wide range of fasteners including, Cup Hooks, Picture Hooks, Hook and Eyes, Wing Nuts, Hex Nuts & Bolts, Square Nuts and Bolts and on damaged nuts and bolts. Application size range: 7 - 19mm. Socket Drive Size: 3/8". Overall Socket Dimensions: 52 x 26mm. CRV.