3.5" Nylon Precision Cleaning Tube Brush Set for Airbrush, Tattoo & Spray Gun diameters vary from 2, 2.5, 3.2, 4 to 5 mm durable stainless steel with nylon bristles Brushes come with a key ring and are about 3.5" long Easily cleans all the hard to reach areas in an airbrush, spray gun, tatto gun any other item with small spaces that need cleaning like the fluid tip, air cap, paint cup can use the brushes for cleaning their equipment like tips, nozzles, grips and tubes