The AIRSTEP mechanical pencil allows you to write for a long time with a single knock. ● Body Colors: Parking Black, Urban White, AIRSTEP Violet, Dusk Pink, Sea Blue (5-color set) ● Mechanism: Clip slide knock type ● Lead Diameter: 0.5mm ● Size: Total length 137.7mm (when guide pipe is stored) / Maximum diameter 10.5mm The "AIRSTEP Light" allows you to continue writing without knocking, for the length of the lead covered by the guide pipe that comes out with a single knock. When the lead is reduced by writing, lightly pressing the tip of the lead against the paper causes the lead and guide pipe to retract into the shaft. The lead is pushed forward by the amount it retracted, but the guide pipe remains in the retracted position, leaving the lead exposed. This mechanism allows you to extend the lead without having to knock each time the lead is reduced, reducing the number of knocks and allowing you to write smoothly. The "Cushion System" is a spring mechanism that maintains the appropriate writing pressure between the lead and the paper. With a normal metal spring, the spring compresses significantly under high writing pressure, and the lead also retracts significantly, making it difficult to write. However, the "AIRSTEP" uses a specially shaped "resin spring." This suppresses the compression of the spring and the retraction of the lead even under high writing pressure, while providing a soft writing feel. In addition, the wavy elastomer grip that fits the fingers and the low center of gravity provided by the metal tip further enhance ease of writing. Thank you for viewing.