Zebra Jimnie Roller Ball Stick Gel Pen, Black Ink, Medium, 24 per BoxCheck Safe Ink! Smooth-flowing water-based pigment gel ink provides effortless writing. Wide barrel with ultra-soft rubber grip. Acid-free, archival-quality. Buy 20 black, get two blue and two red free. Point Size: 0.7 mm; Point Type: Medium; Ink Color(s): Black; Pen Type: Roller Ball.