Water travels through 6 stages of filtration:Crystal Quest® SMART Disposable Under Sink Water Filter System eliminates the impurities of tap water to offer great taste and pureness. The perfect solution for any household, it is quick and easy to install and use, attractive, convenient, and effectively removes many contaminants from water.This solid state water filter uses the latest technologies that blend the adsorption capabilities of coconut shell activated carbon with Eagle Redox Alloy® and more.The unique design allows for a substantial amount of filtration media enabling more contact time with the water. More contact time means better filtration.It can be easily back washed. Semi-annually backwashing of the unit not only ensures balanced filtration and eliminates the potential for channeling, but also back-flushes the unit.Installs neatly under the sink. Comes with an attractive faucet and all necessary installation hardware.Designed in an attractive white housing, conveniently provides 10,000 gallons of water. (1-3 years, or when the flow of water will automatically either stop or slow down greatly.) Please note: When considering installation, if current under sink plumbing is hard copper tubing the saddle valve would be used; for flex tubing the T-valve would be required. While ordering a prompt will require that an installation valve be specified in order to progress through the order entry screen. Also note that the pre-filtration filter located on the countertop page of the website is not available for under sink models.WATER TRAVELS THROUGH 6 STAGES OF FILTRATIONStage 1: Water flows through a one-micron filter pad which removes suspended particles such as silt, sediment, cyst (Giardia, Cryptosporidium), sand, rust, dirt, and other undissolved matter.Stage 2: Water passes through coconut shell granulated activated carbon (Arsenic-Free GAC™). GAC is universally recognized and regularly used as an effective adsorbent for removing a wide variety of organic contaminants, bad taste and odors from drinking water.Stage 3: Water flows through the ion exchange resin, reducing heavy metals such as lead, copper, aluminum, and water hardness.Stage 4 & 5: Water flows through a bed of media made of a special high-purity alloy blend of two dissimilar metals - copper and zinc (Eagle Redox Alloy® 6500 and Eagle Redox Alloy® 9500.) Chlorine and chloramines are instantaneously and almost inexhaustibly oxidized.Stage 6: Water flows through another one-micron filtration pad for further reduction of undesirable particles. The end result is a great reduction or the total elimination of a wide variety of contaminants.• An Air Gap/three-way faucet should be installed to prevent pressure build-up to avoid leaks Min Operating Pressure: 20 psi (pounds per sq. in.)Max Operating Pressure: 60 psi (pounds per sq. in.)Min Operating Temperature: 40 degrees FMax Operating Temperature: 90 degrees FMax Flow Rate: 0.5 gallons per minuteSuggested flow rate is 0.5 or less gallon per minuteStandard 1/4 connections; if 3/8 needed additional conversion package should be orderedDimensions: 3.5L x 10.5H x 3.5WWeight: 6 lbs Product ManualUndersink-Disposable-Manual.pdf