Paint "en plein air" with these portable, refillable Derwent plastic barrel water brushes. There's no water pot required and no spills to worry about, plus they're easy to clean. The small (#1) tip has a fine point for sharp, detailed lines. The medium (#2) tip is best for broad lines. The innovative chisel (#3) tip is best for sharp, fine lines and broad strokes. Water is supplied to the synthetic fiber tip via a leak proof valve.