Juwel BioCarb M Carbon Sponge for Bioflow M (3.0). The filter sponge is enhanced with activated carbon to bind odors, discolorations, and toxic compounds in the water. It is recommended to replace this sponge monthly. Comes in a pack containing two pieces. Suitable for Juwel Rio 125, Rio 180, Rio 240, Vision 180, Trigon 190, Lido 120, and Lido 200.