● Acquired in the 1970s. ● It wasn't used much and has been stored since then. ● The model number is unknown. The nib is 21K. Please refer to the photos for the rest. ● Dimensions: Approximately 115mm (when stored)・143mm (when writing) ● Barrel diameter: Approximately 11mm ● Cap diameter: Approximately 12mm (excluding the clip) ● Mechanism: Cartridge type. ● Ink was applied to the nib for a test write, and then it was rinsed with water. ● There are signs of use, such as minor scratches.