The KMC Controls HFO-0034 CSP In-Line Filter is a compact filtration device designed to protect pneumatic HVAC control systems by removing moisture and contaminants from the air supply. Installed directly in the control line, it ensures clean airflow to actuators, thermostats, and valves, supporting accurate and reliable operation. https://www.partshnc.com/hfo-0034-kmc-controls-in-line-filter-for-csp