Specification: Type: Car Turbo Sound Whistle Material: Aluminum + iron Quantity: 1pc Item Color: red, blue, gold, silver, black. S size is suitable for 1.0-1.6 displacement, exhaust pipe diameter 32-43 mm M size is suitable for the displacement of 1.6-2.0, the exhaust pipe diameter is 37-48 mm X size is suitable for 2.0-2.4 displacement, exhaust pipe diameter 44-55 mm XL size is suitable for displacement above 2.4, exhaust pipe diameter 56-85 mm Installation: 1. Loosen the screw on the turbo sound whistle 2. Place the turbo sound whistle body inside the exhaust muffler with the larger opening facing the inside of the muffler 3. Screw the screws on the turbo sound whistle to tighten the item so it does not fall off while driving 4. Professional installation is always recommended, products damaged through self-installation will not be refunded. Packing list 1*Turbo Sound Whistle Note There might be a bit color distortions due to different computer resolutions. There might be a slight errors due to different hand measurement.