This is a Heisei-era retro princess-style mechanical pencil. As you can see in the photo, there's a cute bottle on top. Originally, it seems like it contained distilled water, but the contents have evaporated due to aging. Since it's unopened, I think it should be fine for writing. It's a retro item. Thank you. This is a set of 6. The lead size is 0.5mm.