Pentel Fude Pen Ink Cartridges, Black Ink, Set of 9, ③ 〇 Pentel Fude Pen, Completely Waterproof Item Numbers: FP-A (old item number) 6, XFP-AD (old item number) 3 Compatible Products: XFP6L (Medium) Type: Unscrews by turning counterclockwise Not compatible with dye-based Pentel Fude Pens (with black cartridges) These are deadstock items I received from an acquaintance who owns a stationery store. Unopened and unused, but they have been stored for a long time, and the packaging has some cloudiness and melted rubber band marks. I do not own the pen body, so I have not been able to test them. Please understand this before purchasing.