【Various Sizes】 Countersink drill bits with countersink included 5 different sizes: 2.8 x 8 mm, 3.0 x 8 mm, 3.2 x 8 mm, 3.5 x 8 mm, 4 x 8 mm. 【Material】 The HSS wood hole saw drill bit is made of high quality alloy steel with higher precision, higher hardness, faster cutting speed and greater strength than ordinary drill bits. 【Fast Chip Removal】 HSS spiral flute drill bit set with a center drill quickly discharges chips from the hole. It can effectively prevent debris accumulation and improve drilling efficiency. 【Adjustable】 Removable and adjustable: Remove the screw with the provided hex wrench and adjust the countersink length to adjust the drilling length of screws of different lengths. 【Versatile】 Suitable for home or professional woodworking projects, countersink drill bit suitable for various soft materials such as wood panels, aluminum panels, plywood, plastic, PVC panels. Not recommended for metals or steel plates.