The CDI 2503-F-ETT Electronic Torque Tester has a 1/2 Inch Drive and can test between 25-250 Ft lbs or 34-339 Nm. Unlike a torque calibration system, which can be used to generate a torque wrench certification, the ETT is a portable, battery powered stand-alone torque tester. It can also be used on AC power. Its primary use is to check the accuracy of dial and click type torque wrenches and torque Screwdrivers to maintain their accuracy in between calibrations. With the addition of a joint rate simulator, ETT can also check stall and clutch type pneumatic and electronic torque tools. This 1/2 Dr torque tester should not be used with any impact or pulse type tools.