This ALPEN drill bit set is a versatile tool for any DIY or professional project. The set includes drill bits of various sizes ranging from 5.5mm to 12mm in diameter, made of high-quality stainless steel. The cylindrical shank and round shank type make it compatible with most drills, while the overall length of 150mm, 200mm, and 220mm provides flexibility for different applications. The drill bits are designed for multi-material use, including wood, stainless steel, brick, glass, tile, concrete, masonry, metal, PVC, stone, and granite. Additionally, the quick-release and self-centering features make it easy to use and provide accurate results. This drill bit set is manufactured in the United Kingdom and comes in a unit quantity of one.