This is a keyaki (Japanese zelkova) burl wood pen from Watanabe Mokkougei. It uses D1 size refills. You can use refills like Acro Ink or Jetstream for comfortable writing. Not only black, but red, blue, and green inks are also available, so you can use your favorite color. I bought this pen, but it has been sitting on my desk, so I'm offering it for sale to someone who will use it. Keyaki wood ages beautifully and develops a unique character with use. It would be fun to use it alongside pencils from Nohara Kougei or Koubou Setsuri to create a matching wooden pen collection. I'm sorry, but I'm not considering lowering the price. Thank you for your understanding. Type: Ballpoint pen Body Material: Wood