Part No. 00-543 (oro2u.com)
5.0mm Valve Guide Hone.
Flex-Hone tools create a cross-hatch finish on the ID of the valve guide bore for better oil retention and less wear on both the valve guide and the valve stem. Recommended RPM: 800 - 1200. Remember, Flex-Hone tools are designed to be used with Honing Oil or and oil based lubricant. Never use

solvents with your Flex-Hone as it will degrade the adhesive bonds in the tool.