This Eaton HAYFLOW filter is made of Polyester Extended Life felt, making it last five times longer than a standard filter bag. Its cartridge-like design makes the HAYFLOW filter easy to replace. This filter also contains a high-quality Kopel SENTINEL seal ring, which eliminates bypass for an extremely efficient filtering process. This filter is size 2 and has a Micron Rating of 5. Sold in box quantities of 8.