This product is a high-quality HVAC control valve that features a normally open design and an impressive Cv rating of 18.5. It is designed to operate within a pressure range of 4-8 pounds and comes with an enclosure for added protection. The valve has a 1 1/4" unglazed connection, making it easy to install in a variety of HVAC systems. With its reliable performance and durable construction, this control valve is an excellent choice for HVAC service technicians looking for a top-of-the-line product to help them get the job done right.