Set Includes: 12PCS hole saw blades, 3/4 (19mm), 7/8 (22mm), 1 (25mm), 1-1/8 (29mm), 1-1/4 (32mm), 1-3/8 (35mm), 1-1/2 (38mm), 1-3/4 (44mm), 2 (51mm), 2-1/8 (54mm), 2-1/4 (57mm), 2-1/2 (64mm), 2 mandrels, 2 hex keys, 1 adapter, 1 spring, 1 extension rod and 3 drill bits for replacement, all in one storage case. Durable and Quality: Bi-metal construction, which has a special flexible steel saw body and high-speed steel cutting teeth, high hardness, wear resistance, corrosion resistance performance, longer service life and sharper. Features: Circular spiral chip flute design, which can remove chips in all directions. Pilot drills are made of premium hss for precise positioning and rapid drilling. Large and small mandrels for different hole saw, easy to install and disassemble. Wide Application: Durable high-speed steel Bi-metal with sharp teeth to use on metal, wood, PVC pipes, drywall, plywood, sheet metal, aluminum, and plastic. Different hole saw sizes meet your different cutting needs. Our Service: The set comes with a customized case for portability. Each item can be placed in a designated slot inside the box for easy access. If you have any problem, please feel free to contact us. Brand Name GMTOOLS Style Name BI Hole Saw 22pcs Item Weight 2.19 Kilograms Part Number CHS-20PCS Manufacturer GMTOOLS Material Type M42, 4241 Compatible Material Metal, Wood, Pvc, Drywall, Plywood, Sheet Metal, Aluminum, Plastic