Worked very well for removing cotton balls in the attic with a dust collector. I was very impressed with how the bag filters the air. The insulation and dust got into the bag and there was a lot less dust in the attic, a lot less than trying to clean everything by hand. I noticed that another user had problems breaking the package. To prevent this I used a chip catcher to remove sharp or heavy objects before anything got into the impeller and hence the bag. Otherwise, when not using a chip catcher, I fed the system insulation by having the inlet next to me while tearing the felt insulation into smaller pieces. Conveniently, this also removed all of the dust I created during the process. I quickly filled the bag, so I will buy more today.