FLEX2PRO Composite represents the latest technology in composite well tanks by Flexcon Industries while incorporating the time-tested, patented design of its steel tanks since 1989. The improved CAD2 diaphragm design in the FLEX2PRO composite is stronger, won't leak air and won't crease or trap water like the bag designs of other composite tanks. It features an independent water chamber consisting of a chlorine-resistant 100% butyl diaphragm with a precision molded copolymer lower water chamber for superior air and water separation. Even more important is the fact that with the water inside the water chamber, our tanks don't sweat like a bag design, eliminating the growth of mold and mildew (an important health concern.) Go with proven Flexcon performance and install the best composite tank on the market, FLEX2PRO Composite.