Features and Benefits: Heavy duty premium grade M2 H.S.S. precision ground cutters for long life in removing spotwelds of high-strength body panels and are packaged in a plastic carrying case. Kit contains: (3) 1cm cutters Arbour assembly (11122) with standard pilot Extra pilot 11,000 Series Rotabroach Cutters......for heavy duty use in sheet metal & materials up to 1.3cm thick. Annular tools that cut clean, burr-free and round holes fast unlike twist drills that push or hole saws that tear through materials. Because they're hollow, there's no dead zone as with a twist drill, so less thrust is required and no deforming of stock or jagged edges occurs. Multiple cutting teeth, precision ground instead of stamped like hole saws, give long tool life. For body shops and frame straighteners, custom building and detailing, aftermarket and trailer hitch installations, rustproofers and under coaters...wherever fast, rugged, and superior quality holes are required Rotabroach"11,000-Series" Cutters are the single answer. Patented tooth geometry also prevents chip clogging when cutting steel, sheet metal, plastic and wood. Arbours for "11,000-Series" cutters fit 1cm and 1.3cm handheld drill chucks and use a spring loaded pilot guide or skip-proof pilots to eliminate pre-drilling operations.