Lenox speed slot bi-metal hole saw design is reinforced to offer strong cut and durability. It has diameter of 2-1/4 inch and has sleek slit that resists tooth strippage. It has high-speed steel teeth that resist breaking and offers extended life. Saw has thick backing plate with holes for drive pins that resists damage due to high torque. It has 2.000 inch pipe and it can cut stainless/mild steel, cast-iron, copper, brass, aluminum, plastics, wood and composition board. It fits 2 length, 5 length snap-back 2 length, 3 length, 6 length or 7 length and standard K36L arbor. Reinforced to cut stronger, last longer and resist tooth strippageThick backing plate with holes for drive pins resists damage due to high torqueHigh speed steel teeth resist breaking and offer extended lifeBi-metal2-1/4 in. DiameterUse this hole saw with a 2L, 3L, 6L, 7L standard arbor or a 2L, 6L snap-back arbor.