The ClimateMaster 33B0006N13 1-Ton Expansion Valve is a precision metering device used in geothermal and conventional HVAC systems to regulate refrigerant flow into the evaporator coil. It senses temperature and pressure changes to modulate refrigerant delivery, optimizing heat absorption and system efficiency. https://www.partshnc.com/33b0006n13-climatemaster-1-ton-expansion-valve