Fitment: For Q5 80A121081DH 80A121081AS Eliminate severe cold shrinkage and leakage: Maintain a constant clamping force during the thermal expansion and contraction cycle to prevent gap leakage caused by winter shrinkage. The automatic radiator pipe has undergone low-temperature toughness treatment to ensure smooth circulation of coolant during cold start Enduring peak pressure impact: The reinforcement layer adopts a composite structure to prevent the external expansion of the pipe wall from causing a decrease in area and a sudden drop in flow velocity. The cooling channel of the car engine provides sufficient safety margin in extreme overheating situations to prevent catastrophic failures caused by pressure exceeding the limit Blocking ozone embrittlement: The outer rubber maintains crack resistance in the engine compartment environment, eliminating surface pulverization and mesh cracks caused by photooxidation. The outer shielding layer of the feed pipe of the car heater is synergistically protected, maintaining integrity and surface elasticity under long-term ozone erosion Inhibiting cavitation wall damage: The smooth lining maintains laminar stability under turbulent conditions, eliminating pressure fluctuations caused by flow velocity fluctuations. The inner wall of the engine coolant return pipe has been treated to maintain its thickness under the dual effects of chemical erosion and bubble impact, Manufacturer: MKVAXR Store