The accuracy of the dual scale (English/Metric) is not effected by hand position. With clockwise and counterclockwise operation, fewer wrenches are needed to complete the job. Easy-to-read, high contrast scale and designed with a laser marked serial number for traceability. N.I.S.T. (National Institute of Standards and Technology) traceable CW certification supplied with each wrench. Also included is 1 removable extension handle for easy force application.