IsoTwist RO TheVertexTheVertex IsoTwist PureWaterMachine is a 5-stage undersink reverse osmosis filter system optimized to treat city water using the existing water pressure. This model makes up to 50 gallons a day of great tasting water, while taking up less space than most other 4 and 5-stage models. The easy twist-off disposable filter cartridges and encapsulated RO membrane are designed to make installation and replacement quick, easy and sanitary. The 5-stages of filtration ensure premium water taste and quality, and the higher production capacity serves larger homes and offices. Great for large service programs or for customers who like to do the filter replacement themselves. The IsoTwist comes complete, ready to install with connection hardware, tubing, faucet and instruction manual.