Size Guide: There are 6 sizes you can choose (8mm/0.31inch - 10mm/0.39inch - 12mm/0.47inch - 15mm/0.59inch - 17mm/0.67inch - 19mm/0.75inch) for your cleaning and polishing requirements Wide Application: The bore cleaning brushes in 6 sizes can reach narrow holes and confined areas easily. You can choose the brush sizes base on your needs to clean kitchen sink drain, machine holes, paint stains, or fine features without damaging surfaces Premium Materials: Stainless steel and brass copper materials make the bore cleaning brushes . There is less chance of rusted when cleaning and polishing What You Get: 24 Pieces of Wire Bore Brush in 6 different sizes with 1/4 inch hex shank for general screwdriver holes. The and right amount of quantity of brushes for higher productivity when cleaning and polishing Gentle Reminder: Please do not exceed 600 rpm and do not turn the bore brush counterclockwise. Use it as a gentle manual brush for better polishing results., Weight: 0.91271376468 Pounds, Manufacturer: Kueohse