uni-ball Vision RT Retractable Roller Ball Pens, Bold Point, Black Ink, Pack of 12 Airplane-safe pen is engineered to eliminate leaks due to changes in cabin pressure. Uni Super Ink is specially formulated to become trapped in paper, helping prevent criminal check washing and other document alteration. Quick-drying, acid-free, archival-quality ink is fade- and water-resistant to last over time. Exclusive uni-flow ink system provides a steady flow of waterproof ink to the point for consistent smoothness and color intensity down to the last drop of ink. Visible ink supply so you know before you run out.