It is a general duct (material: FRP, black gel coat finish) developed to improve the cooling performance by adding a duct and obtain effective downforce. It is a general-purpose item that does not have to choose a car model, and install it in a bonnet or a fender, let it exhaust heat from this duct, increase cooling efficiency, and also cause down force by eliminating air pool. The shape is designed to fit various vehicles and it is designed to be slightly stretched, so it can be attached to loose curved surfaces. The rough size is 450 mm long x 135 mm wide, 2 left and right sets.