Adjustable Turbo Whistle Sound Simulator for Exhaust Pipe Blow Off Valve BOV Muffler Car Accessories Size M XL Features： 1、Make your car sound like a turbo vehicle with the turbo system or blow off valve. 2、Easy to install, no welding or drilling needed. 3、Wrench and black screw is used to fix the item. 4、Lightweight and practical to use. Specification： This whistle will make your car sound like a turbo vehicle with the turbo system or blow off valve. It's easy to install, no welding or drilling needed. Features: Make your car sound like a turbo vehicle with the turbo system or blow off valve. Easy to install, no welding or drilling needed. Wrench and black screw is used to fix the item. Lightweight and practical to use. Specifications: Material: aluminium alloy Size: M, XL (optional) Color: red, blue, black, silver, gold (optional) Item size:      M: length: 100mm / 3.9in, OD: 23mm / 0.9, ID: 21mm / 0.8     XL: length: 115mm / 4.5in, OD: 35mm / 1.4in, ID: 31mm / 1.2in Item weight:      M: 60g / 2.1ounce     XL: 100g / 3.5ounce Package size: 130 * 50 * 50mm / 5.1 * 2.0 * 2.0in Package weight:      M: 75g / 2.6ounce     XL: 120g / 4.2ounce 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 doesn't fall off while driving. 4. Professional installation is always recommended. Package Includes: 1 x Whistle Package List： 1 x Whistle