Product Made of fine quality material, convenient, easy to install and operate, wide range of applications, has a long service life. Characteristics: High hardness, high wear resistance, high strength, flexural strength, anti-breakage. Easy to install and operate, high precision, low noise, burr-free cutting materials. Can be installed on electric hand drills, bench power drills, churn drills and other drills. Suitable for opening holes of all kinds of solid hardwood, sealing plates, press panels, wood products, plastics, plywood and other materials. Specifications: Material: Hard Alloy Color: Silver + Black Quantity: 16 pieces Overall Length: 80mm/3.1in Cutting Diameter: 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 28mm, 30mm, 32mm, 35mm D ...