The Apollo 69ELF114TWG Pressure Reducing Valve with Gauge is a single union valve made of bronze, designed for reducing water pressure. It has an inlet diameter of 3/4 inch and an outlet diameter of 3/4 inch. This unit is suitable for use in various industrial and commercial applications where precise control of water pressure is required. The inclusion of a gauge allows for easy monitoring and adjustment of the pressure reducing valve, ensuring optimal performance and efficiency in plumbing systems.