The world's first mechanical pen with a self-rotating mechanism! The rotation of the lead makes writing line even thanks to the innovative "KURU TOGA ENGINE" mechanism, which is why the lead rotates slowly while writing, and that way it sharpens itself. Lead writes with a clear, thin line of a constant thickness. The high-quality metal barrel has a transparent part where you can see the 3-gear rotating mechanism in operation, the stainless steel tip and built-in eraser under its push button.It comes supplied with 3 HB Uni Nano Dia leads - another innovation - being stronger than any previous lead due to some clever nano-technology. It rotates the lead twice as fast as the M5-450T model, so sharpening is much faster. New lead technology allows writing even when the lead is retracted, protecting it from cracking. Lead diameter: 0.5 mm. The price is per piece, the commercial package is 10 pcs.