Eaton manufactures their SNAP-RING line of bag filters using the best availabe materials. Description PO-1-P04A-50is for a 1 micron, size 04 bag. Made of Polypropylene felt and stainless steel ring, SNAP-RING bags are sewn together using all silicone-free materials. SNAP-RING filter bags are known for their affordability and consistent performance. Part number F3AB00757 comes in box quantities of 50.