Employing a water-based gel ink, signo ensures constant ink flow without blurring or dripping. Its twin-ball mechanism prevents excessive ink flow. When the pen is positioned in a downward position, the ink flows smoothly from the ink flow channel. When the pen is positioned in an upward position, the reverse flow prevention ball works to stop the flow of air into the ink. When you start writing, the ball in the pen rotates to mix the viscous ink causing it to thin. The pen glides on paper, providing a smooth write. Once the ink touches the paper, it hardens quickly when returning to its previous viscosity, which allows you to draw lines that do not blur. Ultra-fine tip featuring a 0.38mm-sized ball enabling precision writing for planners and technical drawings. 0.38mm-sized balls for versatile application at work or school. Self-developed, precision stainless steel tip with superior durability and gel ink that enables you to draw solid, fine lines. Unique twin-ball mechanism prevents ink backflow and leak. Rubber grip that fits comfortably in your hand for ultra-fine precision and fatigue-free writing.