The BOSCH GDS18V-221B25 18V EC Brushless 1/2 In. Impact Wrench with Friction Ring and Thru-hole is designed for driving high-torque bolts, nuts, and anchors. This impact wrench features Auto Bolt Release, which stops rotation when there is no torque on the tool to prevent accidentally dropping bolts and nuts during removal. The tool also has BOSCH's hammer-and-anvil system, which delivers great impact energy. The efficient EC Brushless motor features a long runtime and delivers up to 221 Ft. -Lbs. of torque, 0-3, 400 no-load ipm and 0-2, 400 no-load rpm. This wrench was built with a compact design; it has a 6. 4 In. head length and a weight of just 2. 77 Lbs. The kit includes two next-gen CORE18V 4. 0 Ah compact batteries. Each keeps the power and runtime, while losing the weight, with 21700 cell technology. The CORE18V exceeds the power of the original two-layer 4. 0 Ah battery with half the number of cells. It features the CoolPack 2. 0 heat-management system for extended runtime and battery lifetime.