When the correct torque is reached, the clutch will index and no greater torque will be applied to the screw, even if the operator keeps turning the screwdriver! The TIC Kit will eliminate the expense and problems of buying and keeping track of multiple keys and T-handles, as well as the problems associated with their inability to assure the correct torque. The screwdriver in the TIC Kit is accurate to +/- 6% of the indicated T value, and is calibrated in our ISO 17025 Accredited Calibration Laboratory. It even comes with a FREE NIST-traceable calibration certificate!