2 Size Filter Bag (0.5 Micron) | Polyester Felt | PRM Bag Filters
Polypropylene Felt Filter Bag - 3 Micron
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