Through two, four wires winding each other shaped, winding before the two wires evenly fill the bristles, so that the bristles in the wire winding rotation to a certain stage, the structure of the bristles will then change in shape, into a cylindrical shape. When four wires are wound and shaped, the bristles need to be evenly interlaced, and the pipe brush bristles are made with a higher density. After rotation, trim into any diameter size, and wire wrapped around each other at both ends can be used as a handle or connecting rod. Very convenient The cleaned pipe brush has two methods of use for manual use and tool use, and the pipes that adhere less to the internal dust can be cleaned with a simple manual rotation. For dust with large adhesion, cleaning can be achieved by using a hard bristle that rotates at high speed through a power tool. Tube brush diameter range: 2mm-Max. Tube brush length: min.-2000 mm Cleaning bristle material: PA/PP/PBT/pig/wire/abrasive wire. Customization in a variety of sizes is supported. Tube Brush website:http://www.industrial-brushes.com/tube-brush/