UNIVERSAL BIO MEDIA BAG - Aquarium mesh filter media bag is perfect for small filter media, like pelletized carbon, granular carbon, zeolite, peat, crushed coral, Ammonia remover and ceramic rings, etc. Especially optimal for activated carbon. CUSTOMIZE YOUR AQUARIUM - Mesh filter media bags are perfect for your freshwater, saltwater, or reef tank, small or large. You can choose the filter media for your fish tank according to your expertise, optimize your filter meet the needs of your aquarium or pond and the fish and livestock you have. HIGH QUALITY - The aquarium filter media bag is made of nylon and the zipper is made of plastic which would not rust and produce harmful substances. AND REUSABLE - These unique mesh filter bags are EASY TO FILL AND EMPTY with top zipper design to keep filter media secure. Our bags are , washable, and can be reused. CULTIVATE ECO WATER ENVIRONMENT - Place High Flow zipper mesh bags filled with of media in flowing water. Help to create quality living environment for your fish pet. Purified water quality, rapid probiotics cultivation, restore the high-quality water source in nature Your fish pet farming need a good water source and manage. Colour: black Material: nylon Size: 15x20cm Package Contents: 30 * Aquarium filter bag Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.