I'm selling rings to attach to your ballpoint pen so you can tell what color refill you've put in. The ballpoint pen in the photo is not included. Exclusively for the Frixion ZONE. This is a best-fit ring created using a 3D printer, with numerous adjustments to the thickness, outer diameter, and inner diameter, as well as printing conditions. Simply remove the eraser cap, attach the ring, and replace the cap. The surface also has unevenness to prevent loosening. I made this for myself, but I hope that those who like Frixion ZONE will use it. I'm offering it at a low price, so please give it a try. Please note that the color may vary slightly, so there is a high possibility that the actual product differs from the photo. Color: Cream Salmon Quantity: 4 It has a more reddish feel than the yellow-orange color I'm selling. I haven't compared them, but it feels similar to the Dry Peach refill.