Polishing Felt Filter Pad 100 Micron Bulk 24 ” x 36 ” Ultimate Aquarium Mechanical Prefilter Filtration Media Fresh or Saltwater Improve water quality clarity Durable and Reusable by Awesome Aquatics Available in 50 Micron also Cut Your own Size universal filter fit 24” x 36” 1/8” thick Fine filtering capability100 Micron μ to improve water quality, clarity, and health Can be used as a post polisher or fine pretreatment Universal placement in any flow through type filter. Prefilters, Wet Dry's Sumps, HOB Filters, Canisters, aquaponics, hydroponics, Terrariums, and many more. Strong Durable can be cleaned and Reused, machine washable Can be used singly layered and with other filter mesh sizes to suit your needs.