Camco RV Brass Water Pressure Regulator helps to protect the RV plumbing and hoses from damage caused by high-pressure city water. Reduce water pressure to a safe, consistent 4050psi of operational pressure. Protects equipment and prevents hose failure, to help prolong equipment life. Female garden hose (3/4 - 11-1/2 NH) x Male garden hose (3/4 11-1/2 NH). Patented. For outdoor use only.