Micro Brushes Clean the Tightest Spots Use these 5 micro size brushes to clean airbrush nozzles, R/C plane engines, spokes on model wheels, gear teeth...anytime small parts need cleaning. Nylon bristles scrub away dirt and grease without damaging surfaces. Brushes are 1/16 inch to 5/16 inch dia. by 3 inches long. Includes handle for the four smaller sizes.