Features: After installing this product, the pressure blowing from the exhaust will make your vehicle sound like a turbo vehicle with turbo system or blow off valve. Made of high quality aluminum, light and durable. Easy to install on your car's exhaust pipe. Installation: 1. Loosen the Turbo Sound whistle screw.2. Insert the Turbo Sound whistle into the exhaust pipe.3. Tighten the screw to avoid falling off while driving. Notes: 1. Make sure the exhaust pipe is large and long enough to accommodate the Turbo Sound whistle.2. Professional installation is recommended, products damaged during self-installation will not be refunded.3. Please check and re-tighten the screw regularly. Technical data: Color: blue, black, silver Material: aluminum Size: S, outlet pipe diameter: 32-43mm, length: 11cm Size: M, outlet pipe diameter: 37-48mm, length: 11cm Package includes: 1 Set * Turbo Sound Whistle