Adjustable for infinite range of hole sizes using a quarter of the drill power needed with a hole saw. Features include twin blades for perfect balance, durability, and faster cutting. Cut holes to 17-in. diameter using cordless drills in Sheetrock, Hardie board, plaster, FRP/fiberglass, plywood, OSB, MDF, plastics, rubber, backer board, TJI, T&G, metal siding. Tough clear ABS shields trap dust, adjust for cutting depth and insures straight hole. Kits for 2 in.-6 in., 2 in.-9 in., 2 in.-12 in., and 2 in.-17 in. holes in material 1 1/8 in. thick.