Finerfilters 4 Stage Compact Aquarium Reverse Osmosis Replacement Water Filters and 50 GPD Membrane Removes very high levels of most impurities from the water, ideal for filtering tap water for your Aquarium. Includes: 1 x Sediment Pre-Filter 1 x Post Carbon Filter 1 x Bag of DI Resin 1 x Reverse Osmosis Membrane 50 GPD Please note: this is for RO replacement filters and membrane only. Fittings are not included. PTFE tape will be required when installing fittings.