2pcs 20 inch common water filter activated carbon cartridge clear out 20 inch udf activated carbon filter out water purifier Fits All 20 Filter Housings Highest Quality Guaranteed This 20 Carbon Block will filter out Heavy Metals , Chlorine ,Pesticides , Organic Contaminants and hundreds of alternative dangerous toxins out of your water Dimensions Size: 20 inches (50 cm) Diameter: 2. Lifespan 6 Months Life on Domestic/Average Usage 2500 Gallon Filter Capacity Media High Quality Activated Carbon Block suitability 1) Suitable for all 20 Housings for removing of heavy metals and organic contaminants. Can be used for filtering drinking water through insertion into any regular standard 20 clear out housing. 2) Used as a prefilter in level 2 of all Reverse Osmosis System utilizing 20 prefilters in 20 Housings (used in middle housing as superb protection for the other osmosis membrane). All contrary osmosis methods depend upon this carbon block filter out for prefiltering earlier than the membrane stage. 3) All different water methods have been either filtering of heavy metals and biological contaminants or as a prefilter for filtering/reduction of discoloured water. 4) Used as a prefilter in domestic reverse osmosis techniques , aquarium / pond koi water medication applications , water fed pole and plenty of various uses in 20 housings for treatment of well water or lake water (almost always preceded through a sediment point for properly and lake water filtering) Pictures: