3M Filtrete Oreck Magnesium Ultra Allergen Synthetic Vacuum Bag - 3 bags Fits vacuum models ORECK* Magnesium* and Magnesium* SP(LW100 Series) Uprights. Ultra Allergen bags help trap 99% of airborne pollutants 1 micron or larger, including household dust, dust mite debris, grass and ragweed pollen. Vacuum Bags should be replaced every 30 to 60 days for optimium performance. All vacuum brand and model names are registered trademarks of vacuum manufacturers.