"The ETT (Electronic Torque Tester) is CDI’s portable torque tester. Unlike a torque calibration system, which can be used to generatea 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. It should not be used with any impact or pulse type tools. There are eight models with torque ranges from 10 inch ounces up to 600 foot pounds."