ProFit 1018 0220640CT Carbide Tipped Multi Purpose Kit with Accessories QLH1MP/QLH2MP/QLH1MPCT/QLH2MPCT, Blue, 6-Piece Cut at least 500 holes in wood with each hole saw Cut through Fiber Cement in less than 4 seconds and keep cutting Cut through wood and wood composites, fiber cement, fiber glass, soft bricks, ceramic tiles, lead, plastics, and aerated concrete with these hole saws Quick Lock system - Change between hole saw sizes and styles in seconds, enlarge an existing hole and drill at an extreme angle