A Spindle Mounted Cup Brush is a type of rotary cleaning brush that is designed to be mounted on a spindle machine. It is used for cleaning, deburring, polishing, and finishing metal, plastic, and other materials. The brush is made from metal, plastic, or other abrasive materials, and it is available in various diameters and lengths. The bristles on the brush can be stiff or soft, depending on the desired results. The spindle mounted cup brush is suitable for use on a wide range of materials and surfaces.