Product Description: 1. Wide Application- The 70500 tap socket set fits all number and fractional M. C. T. I. standard taps thru 1/2″. Also fits 1/8″ NPT taps and metric taps thru 12mm manufactured to M. C. T. I. standards. It typically accommodates most common tap sizes, providing a wide range of applications. 2. Work with Extension- These sockets allow users to tap threads in tight or hard-to-reach areas. Used with a standard ratchet, T-handle, or extension, making the set highly compatible with a range of tools. .