Maruha's heavy-duty radiator cap increases the pressure in the cooling system and uses superior materials to the OEM cap. Increasing the pressure of a cooling system allows you to increase the internal coolant temperature which causes heat to dissipate faster, increasing cooling efficiency. The cap also features a silicone seal as opposed to the OEM rubber seal, ensuring a longer life span and increased temperature resistance. Features Designed and Manufactured in Japan Silicone seal 1.1Kg f/cm^2 (15.6 PSI) rad cap