Notise for use: 1. This router bits are designed for portable and desktop woodworking machines and cannot be used on machines such as electric drills and drill presses. 2. Can be used for hard wood, softwood, synthetic board and so on to produce a smooth surface, but to avoid processing copper, iron and other metal materials and sand, stone and other non-wood materials. 3. If you need to use a collect, please select the appropriate size collect. 4. Use appropriate glasses and ear protection when operating.body, clothes and other debris can not be close to the working tool.