Frixion Ball Slim Multi-Color Pen Refills 0.5mm Green, 16 refills These are refills specifically for the Frixion Ball Slim multi-color pen. I bought them thinking they were the right ones, but they weren't, and it feels wasteful to throw them away, so I'm offering them to someone who needs them. Please be aware that these have been handled by a person, so if you are particularly sensitive to that, please refrain from purchasing.