Muji Aluminum Fountain Pen - Pocket Size - With 2 Refill Ink Cartridge Aluminium Fountain Pen - Black, Pen and 2 refill ink cartridges set. Use the stylish aluminium fountain pen to write letters and essays. Close the cap securely after use. Refill ink is available. Water base ink. Fountain pen: Made in Japan. Ink cartridge: Made in Austria.