Pressure Pump Tank, Inline, 5-Gal.5 gallon capacity, inline, pressure pump tank, designed to meet the requirements of & are listed by the national sanitation foundation nsf under ansi nsf std 61, the butyl diaphragm has seamless construction & is designed to flex rather than stretch & crease like bladder tanks, the polypropylene liner for the water reservoir will not flake, chip, crack or peel & does not impart taste & odor to the water, diaphragm, liner isolate water from contact