X-ACTO #8R retractable utility knife blades for X-ACTO 7747 foamboard knife. Lightweight general purpose blade designed to provide an accurate cut through a variety of different medium density materials. The #8 blade also features a dual cutting edge: when one side begins to dull, simply reverse the blade for a fresh cutting edge; twice the blade for the price of one! Also cuts cardboard, plastic, most papers, twine, more. X-ACTO X208 foam board cutter refills. PACKAGE OF 5.