For use with barley pellets, peat, zeolite, carbon pellets, all size bio balls, all types of media rocks and or any Microbe Lift pre colonizes filter media in nylon bags, Industrial strength, Heavy duty draw string closure, Can be placed directly into pond, Easy to clean or change, Folds to fit most filters or skimmers, Large loop for securing to a retrieve line, Medium, 15"" x 16"", Length: 5, Width: 8, Height: 5 SKU: JNSN45870