Amazon.com: 4 Inch Ring Polypropylene Felt Filter Bag 1 Micron 4" x 9" Liquid Aquarium Filter Socks Size 3 - Pack of 2 (4" x 9", 1 Micron) : Pet Supplies
Pentek BP-410-25 Polypropylene Filter Bag (Sold Individually)
10 Micron Filter Bag, Polypropylene Felt W/ Polypro Ring, 7" Dia X 31.5" Long: P10P2P
FSI PONG Bag Filters in Polypropylene with Polyloc - PFC eStore
50P3SH, 50 Micron Polypropylene Felt Bag Filter, #3 Standard Size | Serv-A-Pure
Size 02 5 Micron Polypropylene Standard Felt Filter Bag – Plastic Ring