Hazet 880AKF 3/8-Inch Drive Hexagonal Spark Plug Socket is Made from expert quality material. Application: Installing and removing spark plugs (Wrench size 16 mm = 5/8˝). The fixing clamp reduces the risk of insulator damage. Fixing clamp to hold the spark plug. Largest possible marking for easy identification. Chrome-plated, polished surafce to ensure lasting performance. 6 Spring elements – firm hold of the spark plug. Long design. For manual operation. Stainless and insensitive to heat. Attachment: Square, hollow 10 mm (3/8 inch), Diameter d1 (output side): 21.6 mm. Diameter d2 (drive side): 21.6 mm, length: 64 mm, Output: Outside hexagon profile, Technical Details: Square, hollow 10 mm (3/8 inch) Outside hexagon profile 16 mm 5/8 inch, Weight: 103 g, Width: 10 mm, Wrench size (s1): 16 mm, Wrench Size s (inch): 5/8, Wrench Size s1xs2: 16 x 16.