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 allows you to know the temperature of the water tank accurately without starting the engine. 3. Increases heat resistance performance and enhances tightness of water tank cover. 4. Provides an accurate temperature reading of your coolant. 5. Easy to install, direct bolt-on installation; simply remove the old one and install the new one. Specification Condition: Item Type: Thermostatic Cap Material: Aluminum Alloy + ABS Quantity: 1 Piece Color: As Shown in Picture Function 1. Prevents the water tank from leaking and helps regulate the pressure within the water tank while maintaining proper water level. 2. As water temperature rises, cooling water expands; once pressure exceeds the relief value, the cap's spring mechanism opens, allowing excess coolant to flow into the overflow reservoir. 3. When water temperature decreases, coolant volume reduces, creating a vacuum inside the tank. 4. The cap then opens to draw coolant back from the reservoir into the radiator to maintain balanced water level. Advantage 1. Replacing the standard cap with this thermostatic cap allows accurate monitoring of coolant temperature without engine startup. Package List 1 x Thermostatic Cap