Features: Mesh bag details: The size of the mesh bag is 15 x 20 cm/ 5.9 x 7.87 inches, with a zipper design, you can easily open or close the black mesh bag, bio balls can be applied or in a mesh bag with a plastic zipper. Filter media for pond provides good filtration and beneficial bio filtration growth, removes odor, colors, increase dissolved oxygen levels. Specifications: Material: polypropylene Color: black Bio ball diameter size: 32 mm/ 1.26 inch Bag size: 15 x 20 cm/ 5.9 x 7.87 inches Package includes: 300 x Bio balls filter media 5 x Black mesh bags with zipper Notes: Please allow slight size errors due to manual measurement. Please allow slight color differences due to different displays. Small parts included, please keep them away from little kids to avoid swallowing risk.