The Lenox Tools 3004848L Bi-Metal Speed Slot Hole Saw 3-Inch 76MM is a bi-metal hole saw with a patent pending speed slot on the side. The Speed Slot features a stair case design that allows for easy plug removal with the use a of a screw driver. The slot is wider than most and is placed lower on the hole saw with multiple leverage points to easily eject the plug . The hole saw is 10-Percent taller than traditional hole saws to deliver cleaner cuts through two-by lumber. The Speed Slot efficiently removes saw dust and chips while producing a fast cut and preventing the plug from getting stuck. The saw has a high heat tolerant coating that reduces gumming and has no paint in the inside to make plug removal easier. This new design features up to twice the life of Lenox"s previous model when cutting metal. An enhanced tooth geometry, a thin kerf design and the advanced coating contribute to the efficiency of the cutting process by removing material faster, therefor generating less heat while cutting.