I have a set of pens, mostly mechanical pencils. Some are unused, while others have been used. The orange "Mackee" marker has been used once. The "Opt" pen is slightly yellowed. The eraser has also been used. It's easy to write with. The pen from Heisei Medical College is a ballpoint pen only. The a-gel is 0.3. There are refills available. There were about 20 refills. It's easy to write with. The eraser has also been used. The grip is purple.