3/4 In. F x 3/4 In. F water heater connector. Corrugated stainless steel 304 construction. Approved for residential, commercial, and industrial applications for water supply connections to fixtures. Max Temp: 180 F (degrees Fahrenheit); Max Pressure: 125 psi (pounds per square inch). IAPMO (International Association of Plumbing and Mechanical Officials) listed.