â€Â¢ Worldwide patent. â€Â¢ Chrome-vanadium ratchet gear and fully heat treated handle. â€Â¢ Guaranteed to meet ISO 6789, U.S.Fed.GGG-W686D and ANSI Spec. â€Â¢ Factory calibrated for accuracy to within ± 3% (of reading form B107.14M. 20~100%...