The Inart Fine 2mm Water Brush with Reservoir (110799099) has an integrated reservoir in the handle that eliminates the need for a separate water container, releasing the liquid via a push button whenever the brush body is gently squeezed. The flexible and durable nylon fiber bristles maintain their original shape even after several uses, and the 2mm fine tip is ideal for details, outlines, and small corrections in watercolor, gouache, or watercolor pencils. The reservoir remains closed when the button is not pressed, preventing water leaks inside your backpack or case during transport. It is ideal for those who paint outdoors or while traveling and need a practical detail brush without carrying a separate water cup.