This Taco 400 HY-VENT Automatic Hot Water Air Vent is a top-quality valve suitable for use with water and air. It has a 1/8 inch inlet diameter and a 3/8 inch outlet diameter, with a maximum adjustable pressure of 150 PSI. The valve is made of durable aluminum and is manufactured in Italy by Taco, a trusted brand in the industry. This valve is perfect for use in a variety of settings, including relief valves, valves and manifolds, and hydraulics, pneumatics, pumps, and plumbing. It is ideal for use with hot water and air, and its automatic opening and closing make it easy to use and maintain. Whether you're looking for a reliable valve for your plumbing system or a replacement part for your Taco 400 HY-VENT valve, this is the perfect choice.