Universal Medium Head Thermostatic Water Tank Cap Cover Pressure Temperature Gauge FG05 Features:1. Made of high quality aluminum alloy and ABS material, firm, durable and long service life.2. The thermostatic cap with water temperature gauge can let you know the temperature of the water tank accurately without starting the engine.3. Can increase heat resistance performance and enhance tightness of water tank cover.4. Provides an accurate temperature reading of your coolant.5. Easy to install, direct bolt-on installation, just remove your old one and install the new one.Specification: Condition: 100% New Item Type:Thermostatic Cap Material: Aluminum Alloy + ABSQuantity: 1PcsColor: As Picture ShownFunction:1. Not only to prevent the water tank from leaking, but the larger role is to adjust the pressure of the water tank and maintain the water level of the water tank;2. As the water temperature rises, the cooling water begins to expand, once the pressure relief value is exceeded, the water tank cover spring is opened, the cooling water will flow to the water tank to store the water;3. on the contrary, the water temperature will decrease, the volume of the water will become smaller, and a vacuum will be formed inside the water tank.4. At this time, the water tank cover will also open to suck the water of the auxiliary kettle back into the water tank to keep the water level balanced.Advantage:1. Replacing the D1-SPEC temperature-safety water tank cover allows you to accurately know the temperature of the water tank without having to start the engine;Package List:1 x Thermostatic Cap