This mini electric torque screwdriver increases productivity and enhances product quality through precision torque control and user comfort. The electric screwdriver automatically shuts off once the preset torque is achieved. The assembly power tools are recommended for tightening small screws, nuts and bolts. The electric screwdrivers is NRTL certified from TUV America, Inc. The certification ensures manufacturing companies that they are purchasing and operating a quality and safe tool for its operators. All models are ESD designed and prevent the occurrence of electrostatic discharge, which improves production yields, manufacturing costs, product quality, product reliability, reputation and profitability. Requires STC 30 Plus Transformer (power supply). Mini EF-Series models are compatible with both STC 30 Plus and mini ET-30D transformer (power supply).Model:EF030-E ESDDrive Size:4mm Hios Dr.Range: 3 - 29 cN.m, 0.3 - 2.6 lbf.in, 0.3 - 3 kgf.cm.Tool Weight:8.5 oz.Tool Length:7.66RPM High:1000RPM Low:700Grip Dia:1 1/5"