Pilot FriXion Pen Refills P1AFX725RD, Bulk Pack of 25, 0.7mm Fine, Red Gel Ink. Red Gel Ink. Refills fit FriXion Ball and Clicker erasable gel ink pens. FriXion ball pens have a unique Thermo-Sensitive Gel Ink Formula that disappears with erasing friction. Rewritable-erase and rewrite repeatedly without damaging documents - No wear or tear! Fine point 0.7mm. Writes smooth, erases clean.