Thank you for viewing. This is a fountain pen ink cartridge from the Showa era. Although unused, as you can see in the third photo, it's from a time when a pack of 10 cost 200 yen, so we cannot guarantee its quality as a practical item. How about it for those who collect retro stationery? - Colors: Blue-black, Black - Quantity: 10 cartridges - Brand: Platinum - Application: Fountain pen cartridge *Please also see the profile.