Genuine Royal AR10145 HEPA Filtration Type Y Upright Vacuum Cleaner Bags. Each package contains 2 bags per pack. These are the white colored, synthetic cloth type allergen bags that fit the Royal Pro-Series Upright vacuums. These bags trap 99.97% of all airborne allergens down to as small as .3 microns. These bags are highly recommended for homes that suffer from allergies, or breathing issues such asthma, or for people who want to keep their home as dust free as possible. Because these bags capture a finer particle than the Yellow paper Royal-Aire bags, this means that less dust is going through the motor of the vacuum as well, so the usage of these HEPA bags will also prolong the life of your Royal vacuum motor.