Abbott-Robinson® brushes are made with top quality natural bristles. They're the ideal choice for cleaning and polishing hard-to-reach areas. These well-known, industry-standard brushes excel at applying polishing materials. Each brush has a single row of natural bristles secured in a plated steel hub fastened to a plated ³⁄₃₂" diameter shank. Choose between stiff and soft bristles in 2 diameters. Maximum speed 25,000 RPM. Made in USA. Sold by the piece.