HIGH EFFICIENT FILTRATION HIDROTEK Ro membrane rejects impurities down to 0.0001 micron.High permeated flow and stable salt rejection. Removes up to 98% of contaminants in water (Minimum Rejection 96%). it can remove the particles of heavy metal (primarily fluoride,calcium, magnesium, lead,colloids , chromium and nitrates) and any other 1000+ contaminants from source water. and NSF/ANSI Standard 58 certificated . Universal standard size ​Standard size ( Membrane Dimensions: 11. 75″ Overall Length, 1. 75″ Diameter), Fits all Standard 2″ ID Membrane housing.HIDROTEK supreme quality water filters are universal industry standard size and fit most residential Reverse Osmosis Systems and water filtration systems. Wastewater ratio is 1:2 NSF certificated Thin-film composite RO membrane filters with higher water production rate. 2 gallons waste water will be produced for every gallon pure water. Operation Specification: FEED WATER PRESSURE :35 – 100 PSI TEMPERATE: 40 – 110°F/5-45°C PH :3.0 -11.0 MAX TDS 1000 MG/L TURBIDITY < 1.0 NTU MAX SDI <4.0 HARDNESS < 5 GPG IRON <0.1 Life time :15-24 months as your feed water quality Shelf life: 2 years in original sealed package. More valuable information: Question: What is dimension of the Ro membrane? Answer: It is standard size ( Membrane Dimensions: 11. 75" Overall Length, 1. 75" Diameter), and Fits all Standard 2" ID Membrane Housings. Question:What is the life time? Answer:Our suggestion is 24 months for most tap water (200-500 ppm).usually, you replace membrane depends on usage amount and feed water quality. if tap water is very good quality (200 ppm or less), you may replace the membrane per 36 months. if hard water area, someone replace membrane 6 months or 12 months. it is time to replace new one if flow rate is too less or membrane is cloged. Question:Could I use it if my water Total Dissolved Solids is over 1000 ppm or very hard well water? Answer: Yes, you can use it. even TDS reach 2000 ppm. but you should replace membrane every 12 months or more frequently .less 1000 ppm is our suggestion. Question:Can this be used for brackish water(5000 ppm) or ocean water with high salinity(35000 ppm)? Answer:No. it is just designed for residential tap water use. if you need Ro membrane for brackish water or ocean water and industrial use, Geekpure can provide too, please send email to us. Question:What is in the box? Answer: Just 2 x 75 GPD RO membrane. if you need membrane housing, wrench and flow restrictor ,please buy it separated. Different temperature,different water pressure and feed water quality, the product water capacity and pure water quality is different. That is reason we feel low pure water capacity in the winter, but higher in the summer. Lab test condition : feed water pressure: 70 psi. work temperature: 77 F or 25 C. Nacl concentration: 250 ppm. recovery: 15%. Note: 1. DO NOT FREEZE. 2. Please keep flush new membrane 30 minutes. Because there is protection material in it. then, TDS of pure water will be down to right level. 3. If you have chlorinated water, we recommend you use a Carbon/Sediment Pre-Filter. The residual chlorine in municipal or city water will destroy the membrane. if hardness is too high, we recommend you install water softener before Ro unit. How to replace Ro membrane? 1.Remove the tube from the fitting and twist off the housing cap with wrench. 2.You should pull out old membrane before step 2 when you replace new membrane.(you may use pliers if necessary.) 3.Push the new membrane into housing. 4.Put the housing cap back and tighten it. and connect concern fitting and tube.