Features: After installed this product, the pressure blowing out of your exhaust will make your vehicle sounds like a turbo vehicle with the turbo system or blow off valve. Made of high quality aluminum, light weight and durable. Easy to install on the car's tailpipe. Installation: 1. Loosen the bolt on the Turbo Sound Whistle. 2. Insert the the Turbo Sound Whistle into the tailpipe. 3. Tighten the bolt so as not to fall off while driving. Notes: 1. Please make sure the tailpipe is big and long enough to contain the Turbo Sound Whistle. 2. Professional installation is highly recommended, products damaged through self-installation will not be refunded. 3. Please check and re-tighten the bolt regularly. Specifications: Color: Blue, Black, Silver Material: Aluminum Size: S,Tail Pipe diameter : 32-43mm,Length: 11cm Size: M,Tail Pipe diameter :37-48mm,Length: 11cm Package includes: 1Set * Turbo Sound Whistle