The Signature series files represent the highest possible level of quality in professional filing systems. All Signature files are made in Korea using the finest Japanese made raw materials. 80/80 Half Moon Reinforced Central Core for Added Strength Highest Grade/Durability Sandpaper Individually Wrapped Signature Files are a more premium, durable version of the original INK Pro File with a reinforced central core. Sanitizable File - We recommend either INK Disinfectant Spray or INK Cleaner.