The Otis FG316BP: This All Purpose Receiver Brushes set by Otis provides you with an assortment of brushes for various tasks. Its versatility gives you the power to thoroughly clean areas where unwanted substances such as carbon, powder, and copper residue typically accumulate. Included in the set are brushes with different levels of firmness. The gentlest in the range is the nylon bristled brush. Conversely, the bronze bristled brush offers the most vigorous cleaning. Each pack includes a total of 9 brushes: three each of bronze, nylon, and stainless steel brushes.