Refill for Aspire, PhD, PhD Ultra Ballpoint, Medium, Blue Ink, Sold as 2 refills in one pack. Total of 2 refills. Papermate 4912431PP Refill for Aspire, PhD, PhD Ultra Ballpoint, Medium, Blue Ink, 2/Pack LubriglideR ink system delivers smooth lines and intense color. Expect bold and expressive writing from start to finish. Paper MateR offers high-quality inks you can depend on.