Nutone 6 Gallon Paper Vacuum Bags, 3 Pack Nutone 391 Central Vacuum Bags. 3 bags in pack. Fits CV350, CV352, CV353, CV450, CV653 & CV750. (44186, 63165). 6 gallon two ply electrostatically charged filter bag captures particles down to 0.1 microns at 85% efficiency. Manufacturer Part No.: 391