This is a two piece brush set, Size 3/0 and Size 0, from the 9000 Series by Richeson Art. These brushes are made with performance in mind and are constructed from filament hairs that can withstand harsh brushing techniques. These brushes are perfect for watercolor and acrylic art, and they are easy to handle. They are perfect when you need brushes with a fine, split resistant edge. The black lacquered wood on these brushes makes them easy to work with, and the ferrules have an attractive finish. They are composed of seven different types of fibers that combine to create an effective and high quality tool.