Size: M size is suitable for 1.6-2.0 displacement, exhaust pipe diameter 37-48 mm L size is suitable for the displacement of 2.0-2.4, and the diameter of the exhaust pipe is 44-55 mm Let your car be in full swing, turn your car into a road king, stylish and chic, and improve your driving interest. With this product installed, the pressure from the car's exhaust pipe sounds like a turbo car. Made of high quality aluminum, light and durable, easy to install on the car exhaust pipe, universal type. Place the turbo sound whistle inside the exhaust muffler with the larger opening towards the inside of the muffler. Made of high-quality aluminum, it is lightweight and durable. Easy to install on car exhaust pipe. This whistle can be installed in minutes. 1. Please allow 1-2cm error due to manual measurement, please make sure you don't mind before ordering. 2. Due to the difference of different monitors, the picture may not reflect the actual color of the item. 3. Please confirm the exhaust pipe size before purchasing. The exhaust pipe size must be larger than the product size to be used.