Every wrench is supplied with a calibration certificate to satisfy the requirements of iso 9000robust construction gives accurate results 4 even in arduous working conditionsthe break angle improves accuracy by reducing the possibility of over torquingdual scaled n m and lbf ftall models are also available as production p types with no setting scale accurate results to 4 even in arduous conditions large break angle for accuracy no over torqueing cam control of the mechanism g