Material:Aluminum alloyInstallation:- Loosen the screw on the Turbo Sound Whistle- Place the Turbo Sound Whistle body inside the exhaust muffler with the larger opening facing the inside of the muffler- Screw the screws on to tighten the item so doesn't fall off while drivingSize: STail Pipe diameter : 32-43mmLength: 11cmDisplacement: 1000-1600ccSize: MTail Pipe diameter :37-48mmLength: 11cmDisplacement:1600-2000ccSize:LTail Pipe diameter :44-55mmLength:11cmDisplacement :2000-2400ccSize:XLTail Pipe diameter:56-85mmLength: 12cmDisplacement: 2400+ccFunction:- Make your vehicle sound like a turbo vehicle with the turbo system or blow off valve- Install on Aftermarket muffler, Catback, Axleback muffler it will not produce any sound.Package included:1 x Turbo Sound TwisterDear buyers,you will get 100% as same as the below photo shows: