Sakura - For the artist on the move, simpler the better. The portable and collapsible Koi Waterbrushes are the unique tool that puts a water reservoir at your fingertips. The self contained water reservoir inside the handle delivers water conveniently and directly to the brush tip. The fine flexible nylon brush tip provides excellent watercolor dilution and can produce fine lines or bold broad strokes. The lightweight transparent barrel signals when refilling is needed.