ZDD Pronunciation principle: A whistle that relieves pressure sound, an aluminum whistle clipped on the exhaust pipe, makes a sound through the airflow of the exhaust pipe Durable material: Made of durable material,anti-corrosion and wear resistance.Light weight.Easy to install on the cars tailpipe. Easy to Install: It can be installed in 2 minutes, 1. Loosen the bolt on theTurbo; 2. Insert the the Sound Whistle into the tailpipe; 3. Tighten the bolt so as not to fall off while driving. Make your vehicle sound like a turbo vehicle with the turbo system or blow off valve. General purpose: This exhaust valve is suitable for most vehicles and can be used in cars and motorcycles. It is the ideal accessory for retrofitting vehicles. Warm tips: The turbo sound whistle is not suitble for extremly curved tail pipes. For vehicles with small displacement, choose a large one; and the displacement is large, one because the whistle sounds by the airflow. The displacement is large, the bigger the whistle, the easier it is to make a sound. Applicable models: universal Main material: aluminum alloy Size: XL Color: red + black XL size is suitable for displacement above 2.4 Weight: 125 Pronunciation principle: A whistle that releases a pressure sound, an aluminum whistle clipped on the exhaust pipe, makes a sound through the airflow of the exhaust pipe. Installation method: 1. Loosen the bolts on the turbine whistle. 2. Insert the turbo whistle into the exhaust pipe. 3. Tighten the bolts so as not to fall off when driving. Tips It is best to confirm the inner diameter of the exhaust port before purchasing. If the whistle diameter plus 1cm is greater than or equal to the inner diameter of the exhaust pipe port, it will not be installed. At the same time, please note that the size of the sound is also related to the thrust of the exhaust and personal feelings. Some models may be caused by the original cars low exhaust thrust or modified tail drum. Finally, the key reminder: Does the sound look like, whether it sounds good or not, it has a lot to do with personal feelings and hobbies, it must be an imitated voice You can blow hard against the mouth of the whistle and the whistle can be heard. What can sound is the product is normal, What can sound before installation but cannot sound after installation is the problem of vehicle exhaust thrust. Please check and re-tighten the bolts regularly. One set includes: 2Turbo whistle 2small wrench 2screw