Efficient and cost effective, Challenger tanks are designed with a patented controlled action CAD-2 diaphragm assembly. It features a chlorine resistant 100% butyl diaphragm with a precision molded copolymer polypropylene liner for superior air and water separation. Constructed with an FDA compliant high-grade butyl, the diaphragm assembly seals water in a true non-corrosive chamber. The air chamber is sealed with a fixed O-ring and closed cell foam and will provide many years of leak free and service free life.