Craftsman Mach Series 14-piece 3/8" T-handle Driver and Bit Set The Mach T-Handle driver turns fasteners quickly and continuously with the free spinning collar. The strong square drive on the handle grip allows 3x more torque vs. long arm square drive. The knurled collar can be locked into one of three different positions for maximum control. The 14-piece set includes: 3/8" Drive T-Handle, 3/8" Bit Adapter and 12 screwdriver bits. Craftsman Hand Tool Full Warranty