The standard-sized ink cartridge is a practical addition for fountain pens and rollerball pens. It is compatible with a variety of writing instruments, including models from Schneider and other manufacturers. This cartridge provides a reliable ink supply and is equipped with a ball closure that prevents ink leakage and facilitates handling. The ink in the classic color black ensures clear and precise writing, making it ideal for everyday use at school, in the office, or at home. The cartridge comes in a convenient 30-piece round container, allowing for easy storage and quick access. This ink cartridge is therefore an excellent choice for anyone who values quality and reliability in writing.