Open-cell foam cartridge, fully impregnated with special activated carbon, pH-neutral. Adsorbs dissolved harmful substances, colourants as well as residues of medicaments. After a short period the carbon will lose ist adsorptive power, then it must be replaced with a foam cartridge. Only use once. Content: Activated carbon cartridges for the EHEIM internal filter 2252, 2 pieces.Do you have questions about this article ?