Square Drive Chrome plated with polished steel head and retractable torque setting lever. "Click & Snap" action indicates when the pre-set torque level has been reached. Push through square drive connector to instantly reverse action. 4 easy read scales- Nm, kgf.m, lbf.in x 10, lbf.ft. Calibration tolerance in accordance with DIN ISO6789 & ASME B107.14M-2004. Accuracy = ?4% Supplied with factory tested calibration certificate.