The Otis FG3163NBBZ is a comprehensive set of All Purpose Receiver Brushes by Otis, designed to cater to a variety of cleaning needs. You can select an appropriate brush depending on the area and the extent of cleaning required.These brushes are expertly designed to eliminate stubborn residues of carbon, powder, and copper that often settle in hard-to-reach places. They offer varying levels of intensity for a customised cleaning experience.The set includes a gentle nylon bristled brush, a moderately aggressive blue nylon bristled brush, and a highly aggressive bronze bristled brush. With the Otis FG3163NBBZ, you\'re equipped with three versatile brushes (bronze, nylon, blue nylon) to handle any cleaning situation.