They are fast, accurate, easy to read and have a balanced design for easy one hand operation. The gage can be pressed down on a flat surface and checked so the size should read the same as the set number stamped on the back of the indicator. It can also be checked and set with an optional Ãsetting masterÃ. All ground surfaces are of hardened tool steel AGD design Fast, accurate and easy to read Balanced design for easy one hand operation Can be checked and set with an optional Ãsetting masterà Gage can be pressed down on a flat surface and checked so the size should read the same as the set number stamped on the back of the indicator Holes that need to be accurately checked must have no chamfers or countersinks. FEATURES All ground surfaces are of hardened tool steel AGD design Fast, accurate and easy to read Balanced design for easy one hand operation Can be checked and set with an optional setting master Gage can be pressed down on a flat surface and checked so the size should read the same as the set number stamped on the back of the indicator Holes that need to be accurately checked must have no chamfers or countersinks SPECIFICATIONS Made in America: Yes Type: Hole Gage Range (in): .010 - .040 Graduations (in): .001"