The SUNEX Tools 1/2 in. Premium Crankshaft Socket: 1/2 in. drive 3/16 in. 6-point crankshaft socket for Small Block Chevy V6 and 4 Cylinder, 1.255 ID crank snout with 3/16 in. Dual Size Markings: Features high-visibility laser-etched markings for quick identification even in low-light conditions.