Features: Brand new and high quality Thickened alloy blade head: Widening the blade to increase cutting speed, thickening the blade teeth to be sharply and wear-resistant. Three tooth curved surfaces : evenly distributed force, non vibrating cutter/high concentricity. Hard alloy precisions grinding blade: using special treatments technology of tungsten steel alloy material, the blade edge is sharply, high hardness, and durable. Faster chip removal efficiency: 15 degree blade design for smoothers chip removal. Smooth opening with few burrs: suitable for opening holes in various types of wood. Universal round handle: suitable for hand drills, rechargeable drills, table drills, etc. Specifications: Material: Tungsten steel alloy Size: 15mm, 16mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, 35mm, 32mm, 38mm, 40mm（optional） Package Includes: 1PC x Forstner Tips note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.