Zebra Oil-Based BallPoint Pen Refill for Sharbo X, Minna, SL-F1, Fortia500, Workdash Black Ink, 1.0mm Point (R4C10-BK) Zebra Oil-Based Ballpoint Pen Ink Refill for Shabo X, Mina, SL-F1, Fortia500, Work dash R4C10-BK