This Armstrong 3/4" Drive Micrometer Adjustable Torque Wrench, Ratchet Head is designed with an innovative linear ball bearing mechanism that improves the performance of the wrench by eliminating friction between spring and case for greater accuracy, eliminates speed sensitivity errors, and produces a "crisp audible click" over the entire range. Meets or exceeds ASME B107.14M 1994 and has an accuracy of +/- 3% CW from 20% to 100% of wrench capacity. The twist detent locking ring allows easy setting of desired pre-set torque and prevents accidental change of the torque setting while in use. Created with a lightly knurled and grooved handle provides a comfortable, non-slip grip. A rubber seal between the ratchet head and tube keeps lubrication in and contaminants out of the torque mechanism assuring accuracy and repeatability. Calibration tape is sent with each wrench which verifies the accuracy.