Uni Power Tank 1.0 Refill 42082, Uni-Ball Black Ink, 1.0 mm Bold Point, Pack of 2. With it's pressurized ink technology, the Uni-Ball Power Tank refills meet the challenge of adverse writing conditions, such as: wet surfaces, writing at a downward angle and even extreme cold. The Uni-Ball Power Tank also provides an unusually smooth write and contains Uni Super Ink to guard against document fraud.