Aquapapa 150BB 1.25" Biochemical Bio balls Filter Media for Fish Pond Waterfall Fountain, 150 pcs in a Mesh Bag Bio ball diameter: 1.25" 150 balls in a free mesh bag 12"x10.5"; easy to clean Good to use in different type of filters, and good for both fresh and saltwater tanks. Flat dimensions (with balls): 10.5"x 9"x 3"