Size: The size of this filter sponge is 4.8x11.8cmFunction: The sponge that regularly changes the filter helps to increase the biological capacity, which is conducive to the formation and growth of small organisms, and can better keep the fish tank cleanMaterial: Using environmentally friendly high-grade sponge as filter material, combined with air pump, to achieve the dual fruit effect of oxygenation and filtrationEasy installation: Simply attach the replacement sponge to the arm that holds the foam in placesize: 4.8 x 11.8cmMaterial: spongecolour: BlackPackage Contents:4 x Aquarium Replacement SpongesOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.