US PRO Tools Heavy Duty 11pc Impact Driver Set. This set includes a 1/2 inch Impact Driver Wrench manufactured from Chrome Vanadium Steel with a satin polished finish. It features knurled rings around the circumference of the body for use in oily conditions. To use, simply tap the tail of the handle with a hammer. Ideal for the removal of rusty, corroded, or tight-fitting screws. The set includes 3 x (36mm long) Phillips bits (No's 2, 3, and 4), 3 x (36mm long) Slotted bits (6, 8, and 10mm), 2 x (80mm long) Phillips bits (No's 2 and 3), and 2 x (80mm long) Slotted bits (8mm and 10mm). Supplied in a blow-moulded storage case.