Adjustable torque setting by twisting shaft with main and supplementary scales Lock ring holds selected torque value in place For Clockwise tightening only Click alerts user that torque set has been achieved Rotary slip mechanism prevents over torque by ratcheting after click Accuracy +/-3% of indicated value Mid range models have removable colored resin grip Large models includes hook to assist with turning shaft to set tool for higher values. Accepts 1/4 hex bits (not included) Includes Certificate of Calibration (NIST Traceable Cert offered for additional fee)