Hilti's SIW 18-Volt Li-Ion 3/8 in. Cordless Impact Wrench has the industry's first brushless motor with 3/8 in. drive. When you need to work with thin wall sockets, use this Hilti cordless impact wrench to improve your productivity. Its 3/8 in. friction ring allows quick socket changes which will help you work more efficiently. Productivity increases and operator fatigue decreases with the line of Hilti 18-Volt Cordless Impact Wrenches.