ACDelco GM Original Equipment A/C Evaporator Core Kits contain an evaporator and related system components. The evaporator is a heat exchanger located in the HVAC housing, where it cools and dehumidifies the cabin air. Refrigerant is metered into the evaporator by the orifice tube or expansion valve. All components are GM-recommended replacements for your vehicle’s original components and have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.