Zoobest filter foam (sponge) is made of nontoxic Polyaether. Due to its porous structure it is suitable for biological and mechanical cleaning of fresh & sea water. Filter foam is available in 3 differrent pore sizes 10ppi, 20ppi u. 30ppi and in 2 colors (blue or black). We are able to cut & punch foam to size in different forms, also customer's request!