The MRCOOL H4TXV02 Signature Series 3 to 3.5 Ton TXV Kit is an HVAC accessory designed to regulate refrigerant flow in compatible air conditioning and heat pump systems. It works by using a thermostatic expansion valve (TXV) to adjust refrigerant delivery based on system demand, helping maintain optimal evaporator performance and efficient heat transfer. Commonly used with 3 to 3.5-to... https://www.partshnc.com/mrcoolr-signature-series-txv-kit-h4txv02