DOUBLE-CUT Design: Double groove with cross-wire design, more suitable for low density materials such as wood plastic and aluminum, can quickly remove chips 10 x Head Dia.3mm with Overall Length 38mm and 10 x Head Dia.6mm with Overall Length 43 to 50mm. Made of high-quality tungsten carbide steel, it is sharp, strong, and has a long service life, 10 times more durable than high-speed steel knives. Suitable for use on wood, balsa, wax, slate, marble, steel, welds, stainless steel, brass, copper, bronze, aluminum and many other materials. Universal size 1/8 inch shank diameter, compatible with dremel and most rotary tools with three-jaw chucks and 1/8 inch collets, such as air tools, die grinders, etc. Color: silver Material: tungsten steel Package Contents: 20 x Carbide Rotary Burrs Only the above package content, other products are not included. Note: Light shooting 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.