Durable material and build Made of stainless steel and copper, this 12piece set of wire bore brushes with handles is built for long lasting durability. They are designed to withstand tough cleaning tasks without wearing out or breaking. Versatile cleaning performance Includes 6 different sizes and a practical design to access narrow holes and confined areas. Ideal for cleaning ports, tubes, bearings, cylinders, and more. They effectively remove rust and dirt for thorough, efficient cleaning. Size and compatibility details Diameters: 8 mm, 10 mm, 12 mm, 15 mm, 17 mm, and 19 mm. Each brush is 4 inches long and has a 1/4 inch hex shank, allowing easy mounting on any power drill or die grinder (not included). Use and care guidance Follow the correct usage instructions to optimize performance and prolong life. Do not exceed the recommended rpm and use the appropriate motion. With proper care, these brushes will deliver reliable cleaning results. Practical use scenarios 1) Automotive and machinery components: clean ports, tubes, bearings, and cylinders in engines and equipment. 2) Rust and dirt removal from metal parts such as bolts, fittings, and shafts. 3) Cleaning narrow bores and internal passages in specialized equipment.