New high-performance Hyperflow central vacuum bags are the latest in airflow dynamics and effective filtering all the way down to .3 microns. These are not typical paper bags but more like quilted felt yet very strong and durable. These bags last for years on the shelf and are still able to hold heavy trash without breaking. Dont settle for anything less! Silent Master, Modern Day, MD, Air-Flo, and Stor-Vac central vacuums will perform better and have longer motor life. These bags fit vacuums OVER 34 inches tall (total length top to bottom) and replace older #721-5 bags. Although this bag may seem big, it was designed this way. Our bag has more area to filter air. After inserting the bag open it up inside the vacuum by pushing down and out around the sides. Elastic top bag. Comes in a 5-pack.