High speed, heat resistant Carbide Steel teeth welded to a durable alloy backing and capExceptionally strong, safe, and shatter resistant.Includes:(6) Holesaws: 5/8 in, 25/32 in, 1 in, 1 1/4 in, 1 9/16 in, 2 inA4 Hole Saw Arbor (1/4 inch shank) with Pilot DrillA10 Hole Saw Arbor (11/32 inch shank) with Pilot DrillA12 Arbor AdapterA7 Ejector Spring