The First Company 9EVR410-4 Thermostatic Expansion Valve is an HVAC component designed to regulate R-410A refrigerant flow in compatible air handlers and fan coil units, including First Company 30HBX and 36HBX models. It automatically adjusts refrigerant flow into the evaporator based on cooling demand and operating conditions, supporting effective heat absorption and system performan... https://www.partshnc.com/9evr410-4-first-company-thermostatic-expansion-valve-r-410