Camco’s Brass Water Pressure Regulator with Gauge helps protect your RV plumbing and hoses from damage caused by high-pressure city water. It features an easy-to-read gauge. Green color on the gauge indicates that the regulated pressure is between 40-50 psi. This pressure regulator attaches easily with convenient 0.75″ garden hose treads. The pressure is factory preset at 40-50lbs per square inch. Patented. For outdoor use only.