This is a highly popular, limited-edition model produced in 2011. The model name "O" stands for "Over," and it creates a beautiful, deep color with thick green bands of varying shades layered on top of each other. The barrel and cap use a material carved from translucent acrylic blocks, allowing light to pass through and creating a unique texture. The condition is very good, a near-mint item with only a few test writings. There are no defects, and no personal names are engraved. The nib width is M (Medium). It's a well-balanced nib width, and it pairs perfectly with the mid-size M600 barrel. It's a versatile writing experience suitable for everyday use, letters, and note-taking. Currently, many pens on the market have not been tested for functionality or have issues such as cracks or ink clogging, but this pen has been tested for functionality and authenticity. In the unlikely event that the product is a fake, we will provide a full refund, including shipping costs. Please note that this listing is for the pen body only. If you would like the box, it is available for an additional 1,800 yen. Please let us know in advance if you would like it.