Heavy Duty : Max Water NSF Certified tanks are built to last. With 100 PSI max working and a smooth internal air vent cap (to prevent diaphragm damage). This tank is built to last years at a time without the need to change. The tank comes pre charged at 6 PSI. Wide Rage of Application : 1/4" stainless Steel Connection built for Reverse Osmosis water storage tank, pump tank & thermal tank applications. Storage & Dimension : Water storage capacity 4.4 gallon approx @ 100 PSI & 3.2 gallon @ 60 PSI; dimension approx 14" Height , 11" Diameter. Quality Tested: We consistently provide products and services that meet customer quality requirements. Why Max Water : We have 15+ years of experience in water filtration industry providing solution with a smile to millions of families. Make Max Water your solution to all your filtration needs.