Features: 1Beautiful appearance, wonderful choice for auto car modification. 2Made of quality aluminum alloy material, safety and durable to use. 3Easy installation, directly replacement, installed on a modified car turbo. 4The exquisite design allows it to be used as an ornament as well. 5This is a whistle that simulates the sound of a turbine's pressure relief , which is attached to the exhaust pipe, makes a sound through the airflow from the exhaust pipe. Condition: 100% New Item Type: Turbo Sound Whistle Material: Aluminium Alloy Color: Blue Size: S, M(Optional) Installation Instructions: Clamp on the tail end of the exhaust pipe. Tips: 1. If the car is installed inside the tail throat, it may be that the car's airflow is not large enough. It is not enough to concentrate the whistle. The parents can install it outside and use the wind. Because the wind's airflow is bigger than the car's airflow, it's easier to blow. 2. Product inspection can use the mouth to blow the air into the tight whistle, and you can hear the whistle. If you can blow the product for normal products, you can contact us to return the goods. It is the problem of the exhaust force of the car that can be blown and not rang after installation. 3. About the size selection: First, please measure the inner diameter of your own exhaust pipe. Under the premise of proper installation size, try to choose a large size. For vehicles with small displacement, choose a large size, and a large displacement, you can choose a small one, because the principle of whistle sound is by airflow, the displacement is large, the bigger the whistle, the easier it is to make a sound. Package included:1 x Turbo Sound Whistle