The K Tool International 12-pc 1/2" Drive Professional Impact Driver Set, No. KTI71701, provides technicians the most common size bits and can handle rusted and frozen screws. With its heat treated and hardened alloy steal it is built for rugged use. The professional grade impact comes in a sturdy metal case with storage tray to keep all 12 pieces organized. The set includes: 1/2" impact driver, 1/2" drive 5/16" bit holder, Phillips bits (PH2, PH3, and PH3 Xtra long), slotted bits (8mm and 10mm), and bolt removers (M3-M6, M6-M8, M8-M11, M11-M14, and M14-M19).