Pilot Frixion Ball Knock Click Retractable Erasable Gel Ink Pens,fine Point, - 0.5 Mm - Black,blue,red,blue Black Ink- Each 1 Pen- Value Set of 4 Combines the convenience of a retractable with the incredible FriXion erasable gel ink Erase and rewrite repeatedly without damaging documents - Eraser is at the top of the pen, tip is retractable by pressing clip down Unique Thermo-Sensitive gel ink formula disappears with erasing friction