Shop Vac Micro Filter Bag....substitute
I have the 1 gallon Shop Vac and it uses the regular size filters.
Tried to find Shop Vac Micro Filters to no avail. Micro Filters are suppose to filter out 99% making them great for people with allergies.
I substituted a Micro Filter bag for the Hoover Upright Type A, cutting bag just below the hole. Folded down the top to desired length and then slipped over the foam filter and put the ring up high on it. The ring is usually used for wet pick up, works great to hold the bag up high.
Hope this will be of help to others.