Feature: Hole Size: Coarse, The Hole Measures 2Mm, Works For Large Filter Media, Allows Water To Flow Through Instantaneous; Good For Use With Bio Balls, Zeolite, Ceramic Media, Rock, And Crushed Coral And Any Other Aquarium Filter Media. Fit Perfectly In A Variety Of Filters Including Canister Filters, Power Filters, Sumps, Wet/Dry Filters And Pond Filtration Systems To Hold Media Together And Keep Aquarium Clean Plastic Zipper Design Can Be Used For Both Freshwater And Saltwater Tank.

These Unique Mesh Filter Bags Are Easy To Fill And Empty With Top Zipper Design To Keep Filter Media Secure. Our Bags Are Durable, Washable, And Can Be Reused. Specification: Filter Media Mesh Bags Plastic Zipper Dimension: Small: 3 X 8 Large: 5.5 X8 Hole Size: 2Mm Includes: 10 Pcs Mesh Bags