CNZ BB300 Bio-Balls Filter Media for Fish Pond Waterfall Fountain, 1.25-inch Includes a free mesh bag Will not compact like other soft media, reduces channeling of water around media 1.25 Inch in diameter, black in color, approximately 300 per bag These plastic bio-balls are a great media for use in all types of filters Weight: 1500g Dimension: approximately 13" x 9.5" x 5.5"