The Jobsmart 1/2-in drive 20-150 ft. lbs. torque wrench is calibrated to +/- 4% clockwise accuracy in the upper 80% of torque range. It features a twist collar that locks torque setting in place and is designed to audible click when torque setting is reached. It has a 24-tooth ratchet design that requires a 15-degree swing arc to turn fasteners. Its ergonomic handle allows for a comfortable grip when applying torque.Note - over torqueing outside of calibrated range increases the risk of stripping the fastener and causing loss of accuracy.