The new Eheim Media Set is a complete filter media kit for crystal clear, healthy water and long intervals between cleaning. Eheim filter media are developed in the Eheim laboratories and manufactured using only the best quality materials. These materials are sourced using the highest quality control methods and are free of toxic substances.Content:2x 2 litres EHFIMECHMechanical filtration with EHFIMECH: Effectively traps and breaks down all coarse dirt particles from water bevor further filtration process.1 Coarse filter padPhenol free (toxic chemical normally found in other media), large pore sponge giving both mechanical and biological filtration, with even water flow-through.4x 2 litres SUBSTRATproBio-filtration with SUBSTRATpro: excellent micro-pore structure for quick colonisation of necessary bacteria to achieve faster decomposition of toxins. Anti-clogging pearl-shaped structure ensures better flow-through, giving 50% more efficiency due to longer intervals between cleaning. No