Derwent Push Button Water Tank Brush Set Assorted pointed and chisel-ended watercolor brushes for a wide range of strokes. Large body for water with push button for easy control of water outlet. Ideal for use with water soluble paints and pencils. Assorted pointed and chisel-ended watercolor brushes for a wide range of strokes. Large body for water with push button for easy control of water output.Ideal for use with water soluble paints and pencils. Portable and convenient for indoor and outdoor use. The strong nylon fiber tip maintains its shape and point for continuous use and comes with a protective cap. Comfortable and leak-proof handling. Water-reservoir brushes are perfect for water-based or runny materials. They also work perfectly with distress scrapbooking inks. Brand: Derwent.