The bags are constructed out of heavy duty paper with heavily sealed seams so there is b no chance of tearing the bag. Due to the shape of the bag and geometry of the vacuum, when using the HEPA or Micron Filters, the bag contacts one face of the filter and the top must be placed on the vacuum carefully. The bags have to be changed when about half full as opposed to my Hoover Wind Tunnel HEPA bags at 75% + which do not require an additional HEPA filter. Making the vacuum's motor further offset would improve the filling of their bag, and they should either offer HEPA bags or reduce their HEPA filter price to what the Cleanstream HEPA filter costs. The intake size makes using Fein's bag mandatory. They work fine.