When the coolant pressure in the radiator exceeds the pressure cap setting, the coolant will flow into the radiator coolant overflow tank. Made of high-quality lightweight billet aluminum, TIG welded, matte surface, with O-ring gasket, resistant to high temperature and pressure, durable and non-leakage.The bottom with drain valve, make it easier to clean and reusable constantly. The cap is a knurled easy-open and easy-close design. The side transparent hose can monitor the volume of coolant in the overflow bottle at any time. Universal for most vehicles. Compatible with Honda Toyota Subaru Mitsubishi Mazda Ford Acura Nissan Infiniti Lexus Scion Jeep Dodge GM etc. There are 4 specifications to choose from. 1.1L Silver 2.1L black 3.2L Silver 4.2L black Product net weight: 539g/781g Color: black, silver Material: aluminum alloy Quantity: 1pcs Packing list: 1*oil pot 2*connector Only the above package contents are included, other products are not included. Note: Reflection of light and different monitors may cause the item's color to be slightly different from the actual item. Measurements allow +/- 1-3 cm.