【High quality】 – these do dredging drill bits are made of high quality alloy steel. Which provide excellent cutting performance. High hardness and wear resistance, convenient and fast hole drilling 【Removable and Adjustable】Use the included wrench do remove the screw and adjust the length of the countersunk hole to adjust the drilling length of screws of different lengths. This drill is a good helper in everyday life and improves work efficiency. 【Wide application】 Do wood, plastic, soft metal, fiberboard, aluminum alloy dredges, holes, etc. 【High efficiency】Spiral drill with center drill will quickly unload the chips from the hole. Can effectively prevent contaminant retention buildup and improve drilling efficiency Material Stal Alloy Finish Type Aluminum Shank Type Round Brand Frunimall Surface Recommendation Wood, Plastic, Metal Specification: Material: YG8 Alloy Color: Silver Orange Size: 2,8 x 8 mm / 3,0 x 8 mm / 3,2 x 8 mm / 4 x 8 mm Rod Type: Round Stem Diameter: 8 mm ) The package includes: 5 pcs. x drill bit 5 pcs. x key 5 x screws.