KTI71700 - 3/8" Impact Driver with 4-piece 5/16" Bit Set Features and Benefits: 3/8" square handheld driver Ideal for loosening rusted screws, nuts and bolts Packaged in a metal box Includes detachable bit holder and four 5/16" hex bits Bits also available individually 3/8" square handheld driver includes detachable bit holder and four 5/16" hex bits. Ideal for loosening rusted screws, nuts and bolts.