After a few years of use, the filter bags that come with most dust collectors eventually pack up with the finest dust. The reduced air flow prevents the machine from collecting as well as it did when new resulting in poorer air filtration in your shop. Renew that tired out filter with this new one. They are made by the same manufacturer using the same felt filter material that supplies all the Taiwanese made dust collectors.
1 to 2 micron rating.
It's 32 inches tall from the bottom edge to the top seam where they sew the 20 inch circle to form the top of the bag.