Stanley Proto J6014C 1/2-Inch Drive Ratcheting Head Micrometer Torque Wrench, 50-250-Feet Pound Calibrated to +/- 3% clockwise direction and +/- 6% counter clockwise at 20% to 100% of full scale Calibration is accomplished by manual loading the torque wrenches Manufactured to meet standard industrial torque applications, general industry, heavy equipment, and maintenance