Royal / Hoover Back Pack HEPA Filter fits Hoover backpack vacuum models C2401, C-2401, C2401010, C-2401010 and C2401-010 and fits Royal backpack vacuum models RY4001 and RY-4001. Genuine Hoover / Royal vacuum cleaner filter.
Royal Backpack Pre-Motor Filters are about 8 inches round. Made of felt and have cutouts in them. Fits Royal vacuum cleaner models RY4000 and RY4001. Genuine five pack of Royal vacuum cleaner filters..