Made of heat-treated steel. Use with a 3/8 inch driver. Inside diameter is 24 millimeter. Designed to fit oil filter and clutch hub nut on many Honda models (single and twin cylinder machines). Fits: most pre-78 CB, CL, CT, SL and XL models, XR200 80-84,XR200R 81-01, XR250L 91-96, XR250R 86-95 and GL1000 75-77. Replaces large end of 07716-0020100 OEM tool.