The Medium Zip Bag™ is a mesh bag for holding filtration media. It is available in a 32 cm x 14 cm (12.5” x 5.5”) size , easily holds 1 liter of filtration media, and it comes with a convenient corrosion-proof zipper. It has a mesh size that is capable of holding intermediate and larger sized filter media including PhosGuard™, MatrixCarbon™, SeaGel™, de❊nitrate™, Renew™, Matrix™, Zeolite™.