Excellent HEPA Packs. Dust does not get through these bags. They're expensive, but you won't be disappointed with this quality. I wish I could find a way to attach a zipper or velcro to it so I can empty it and reuse it. This is a cloth-like layering material and I'm sure they could be reused many times if you could empty them. Throwing complete rubbish into a landfill seems like a waste of time. They are used in my Garage Vac Pro and are huge so will last a long time. I use them in my stable for general cleaning as well as washing trucks, cars and horse trailers (equipment). Great bags and the Pro Garage Vacuum is a great cleaning system.