The Tekton 1/2 Inch Drive Split Beam Torque Wrench is accurate to +-4% throughout its entire 40-250 foot-pound range. Each wrench is serialized and calibrated according to the ASME B107.300-2010 standard. The detailed test results are recorded on the included calibration certificate. Unlike other torque wrench designs, this wrench can be stored at any torque setting without losing accuracy.