The Tridon Coolant Expansion Tank is a direct-fit replacement for Audi A4 2.0L Turbo Petrol models built from 2021 to 2023. Pressure rating is 125kPa; running the wrong rating will either boil the coolant or stress the radiator seams. The Plastic construction resists coolant additives, heat cycling and pressure fatigue. Opening temperature is 80 degrees Celsius, matching the engine management calibration. Hose is moulded to the factory shape with the correct bends, clip locations and internal diameter. Replace the cap, thermostat and hoses together on high-kilometre vehicles - they are cheap compared with a head gasket. Supplied new and backed by a 24 Months warranty.