Genuine OEM Hyundai Radiator Cap, part number 25330D3000. This essential component seals the cooling system, maintaining the correct pressure to prevent coolant boil-over and ensure efficient engine cooling. It is typically located on the radiator or coolant expansion tank. Made from durable black plastic, this cap features standard warning symbols. Genuine OEM radiator caps are engineered to precise pressure specifications, critical for the proper function and longevity of the entire engine cooling system.