1. The function is to keep the temperature of the car before it reaches the normal temperature. The water of this engine can only circulate in the upper part of the water tank. It is a so-called small cycle, which makes the engine heat up quickly because it is at low temperature. It is very fuel-intensive and the most damage to the car, which will bring a series of problems of carbon deposition, and then it can be opened after exceeding the normal temperature, allowing the water to circulate in the entire water tank for rapid heat dissipation. 2. Easy to install. 3. Made of plastic and copper, which is durable. 4. OE number: 17111437362. Please check the OE number before placing order. 5. Fits for: BMW E46 E53 E83 E85 E86 X3
