Derwent Art Supplies, Waterbrush, Small Tip (2300123) A handy water holder and brush in one for "en plein air" pursuits; water flows to the synthetic fiber tip via a leak-proof valve Small brush is great for detail work; designed for use in the field Also sold in medium (2301760) and chisel tip (2301974) or a 3-pc. multi pack (2301975)