Black Velvet Watercolor Brushes are made with a blend of squirrel and synthetic hairs. This  round series S3000S is a great multi use round detail brush: lifts color gently, multiple layer glazing, maximum carrying capacity. 

Clean with  or water. 
Brush care tips can be found 

8 1/4" long x 7/8" brush length (fine at the tip and wider at the base)

Dee Silver wondered whether there was a market in the U.S. for high quality brushes. Would people pay more for quality? Was the market enough for a realistic business? Would she be better off in Europe? In 1991, she founded Silver Brush and over the years her questions have been answered by the natural enthusiasm of customers. She started in the New York region but now her brushes are sold and relied upon by artists all over the country and throughout the world.