HOBBY Ceramlit (Ceramic Rings)Consists of ceramic capillary filter tubes (10_x_10_mm) which serve as a mechanical advance filter and biological pre filter material. The structure of the Ceramlit hollow bodies induces an optimum flow rate and prevents clogging up of your filter with coarse dirt. ceramic filter tubes for mechanical preliminary filtering ideal for collecting coarser dirt particles floating in the water hollow body structure ensures an optimum flow rate and prevents a