Giant metal refill in ISO format G2. Writing colour miscellaneous. Medium or fine line width (M/f), waterproof according to ink standard ISO 12757-2. The wear-resistant stainless steel tip guarantees that the large ink supply can be fully used and does not smear. Fits all Schneider Plug+Play ballpoint pens as well as lots of other pen types. Premium quality for approx. 10,000 m clean writing.