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. Notes: 1.This turbo sound is not suitable for extremly curved pipes, if curvature is minor,the fitting bracket mabe slightly curved to match the tail pipe. 2.Not suitable for pipes having smaller or bigger diameter than 56mm to 80mm. 3.For taill pipes with deflected outlet,it might be necessary to modify slightly the shape to allow installation. 4.Prior to the purchase and installation, please make sure that the interior of the tail pipe is suitable and sufficiently long(11-12cm) to contain the turbo sound device. 5.Periodically (after 500-800km) check and re-tighten the bolt and rock nut.