We solemnly promise that the quality of our products is absolutely wonderful !!!Welcom to our shop to choose others !Features: Dual saver fan spins with the engine speed while generating a maximum force that creates powerful airflow into the combustion chamber at high speed The propeller sucks the airflow into the combustion chamber at a higher speed resulting atomized burning which increase horse power and saves gasoline Rubber holder can increase the diameter of fan for fitting in the tube Maximum Speed Movement: 55，000R / Min Size (Dia. x L): Approx. 2.5 x 2.95 inch / 6.4 x 7.5 cm Body Diameter with Rubber Holders Wrapped on: Approx. 2.8 inch / 7 cm Material: Aluminum alloy and rubber Color: Blue Installation: Remove air inlet hose located between air purifier Put the intake fan into the air inlet hose Use rubber holder attached to fit into the tube with a larger diameter Package Included: 1 x Fuel Saver Fan 3 x Rubber Holder (We recommend to buy more than two.It is do really good quality.)Delivery time is about 8-20 Day!