The Pentel Aquash Water Brush Flat has durable nylon bristles and a 10ml refillable water tank. When filled, the brush can be gently squeezed to wet the bristles, making them ideal for watercolour, ink and watercolour pencil work when outdoors or travelling. This handy brush is ideal for the artist on the move, and would be useful for a variety of different techniques. The brush can also be used to mix watercolours or inks within the tank, so that you can give the perfect amount of colour every time. Great for watercolour artists, designers, painting classes and craft and hobby work.