1. Blade is made of exceeding quality alloy, perfect sintering technology, and expectancy. 2. The positioning is made of powder alloy die-casting, make use of curve design, good for chip removal and drill Special removeable strongback design makes drill easier. 3. Could be used for most handheld drill/wireless drill/table drill for wood products hole drilling with smooth hole. Colour:Blue + Silver Material:Cemented carbide Size:15mm/20mm/25mm/30mm/35mmm Package Contents: 5 * 15-35mm Adjustable Positioning Woodworking tools Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.