About this item Large Mesh Design: Each aquarium filter media bag measures 7.87″ x 5.51″ (2014cm) with a 3.2mm opening, ideal for large filter materials like ceramic rings, bio balls, lava rocks, or crushed coral to enhance water circulation and clarity Premium Material & Durability: Made of high-strength black nylon, these filter media bag are tear-resistant, washable, and reusable. The mesh size keeps media secure while allowing maximum water flow in both freshwater and saltwater tanks Secure Zipper Closure: Designed with a sturdy plastic zipper, the aquarium filter bags ensure filter media stay in place during use. Easier to open, refill, and clean than drawstring bagsno more loose media clogging your pump Multipurpose Compatibility: Perfect mesh bags for aquarium substrate, compatible with most aquarium filtration systems such as canister filters, sump filters, and pond setups. Fits a variety of media including activated carbon and zeolite Value P