The Apollo Expansion PEX 3/4 in. Bronze Double Union PEX-A Water Pressure Regulator w/ Gauge sets a new standard in water pressure regulation. It is designed to reduce incoming water pressures to a safe level to protect plumbing fixtures and appliances. With simple adjustability and an instant read, color-coded dial to provide downstream pressure measurement, this valve solves all of the annoyances of pressure regulators from the past. It also assists in the control of pressure surges from entering the structure from the water main to further protect fixtures and appliances.   Excessive high pressure within a plumbing system can cause damage over time.   A pressure regulator should be installed after the main line to help protect plumbing. Featuring a superior flow rate, durable bronze construction, and fitted with Apollo ExpansionPEX brass barb unions, the 36ELF can be easily integrated into any cold-expansion PEX-A piping system.