The round brushes feature Kazan squirrel synthetic fiber, a plastic ferrule, and a black metallic cap-handle. Series 1330 and 1337 stand out as premier choices for watercolor pocket brushes, seamlessly blending traditional elegance with innovative design. Their heads are crafted from natural squirrel hair in series 1330 and squirrel synthetic fiber in 1337, firmly secured to tumbled handles with special bi-component glue. The plastic ferrules, bound with golden wire, ensure stability and exceptional water resistance. Doubling as handles, the caps come in matte golden for series 1330 and matte black for series 1337. Both series conveniently fit into pocket cases, including wood (555V), faux-leather big or small cases (4326V or 2326V), and the cherry wooden palette (111V).