Derwent Art Supplies, Waterbrush, 3 Pack (2301975) Set of water brushes gives you the perfect flexibility out in the field; set includes a small, medium and chisel tip brush Water flows to the synthetic fiber tip via a leak-proof valve; each brush includes a number, so you know what you're reaching for Also sold individually: Small (2300123), Chisel Tip (2301974) or Medium (2301760)