Sanford uni-ball power tank ballpoint retractable pen, 1.0mm, blue ink, dozen power tank retractable pen offers a pressurized ballpoint for extreme writing performance. Use it to write on wet surfaces, in extreme cold, at odd angles, even upside down. Uni super ink helps prevent check and document fraud. Textured grip offers great writing comfort. Refillable. Textured grip. this product arrives to most customers in 2-3 business days.