Here’s a breakdown of its key features:

1. Pressure Regulation: The cap helps maintain the radiator's internal pressure, typically rated between 13-18 psi, depending on the vehicle. By maintaining pressure, it raises the coolant’s boiling point, allowing the engine to operate efficiently at higher temperatures without boiling over.

2. Pressure Relief Valve: When the pressure exceeds a certain point, the cap’s valve opens to release excess pressure, preventing damage to the cooling system components like hoses or the radiator itself.

3. Vacuum Valve: This valve allows coolant to return from the overflow tank back into the radiator when the engine cools down, ensuring the system maintains proper coolant levels.