Radiator Coolant Expansion Tank with Cap compatible with 2017-2019 XT4 and XT6 models as well as Acadia and Terrain vehicles.This component is designed to hold excess coolant and maintain proper pressure within the cooling system.It includes a cap to seal the tank and regulate system pressure.The tank is constructed to meet specifications for fitment and function. Important: This is an independent aftermarket part.Brand/model references serve only to show compatibility.