This is a Jinhao knock-type fountain pen. Thank you for viewing. ・JINHAO 20 series fountain pen. ・Nib: Stainless steel ・Body: Resin ・Size: EF (similar to Japanese MF) ・Mechanism: Converter and cartridge compatible ・Length: Approximately 142mm ・Thickness: Approximately 13mm (shaft) ・Weight: Approximately 22g ・Accessories: Built-in converter ・A screw-type converter is included, so you can use it immediately if you have ink. Pilot cartridges also seem to be usable.