1. The carbide tipped teeth hardness HRC overs 80. It’s more hard, more shape, longer life. Up to 10X times more cuts than standard bi-metal hole saw drilling for hardy plank. Up to 5X times more speed than standard bi-metal hole saw drilling for Hardy plank. 2. The big slot design and special teeth are to remove the plug easily. Up to 5 times faster than standard hole saw. 3. Max cutting depth:2.36 “ ( 60 mm) . Replaced the following drill bits: Spade bit, forstner bit, auger bit, bi-metal hole saw. 4. Ideal drilling for multiple materials: hardy plank, hard wood（not with nail), drywall, MDF, fiberglass, wall tile, air brick, plasterboard. Cutting material MOHS hardness：Not up to 6. For use in standard rotary drills. Not for use in Hammer mode. 5. Package includes: 3” 3-5/8″ 76 mm, 92 mm hole saw, 1 x 0.43” (11 mm) shank arbor, 1 x 4.3” (110 mm) silver HSS pilot drill bit for wood. 1 x 4.3” (110 mm) carbide tipped pilot drill bit for hardy plank, wood, stone. 3, 3-5/8 inch 76, 92 mm dia carbide tipped hole saw kit, 2.36” deep cutting for multiple material, hardy plank, hard wood, MDF, wall tile, air brick, 10X more cuts, 5X more faster