It is a hard shell cover, mounted on the roof of the traction car cab, refrigerated car guide hood is generally made of thin steel plate, but also useful FRP paste system. There are two kinds of guide hood: fixed type and adjustable type. After the fixed guide hood is installed on the roof of the cab, its elevation Angle is immutable. The adjustable guide hood has an elevation adjustment bar, which can adapt to different cargo height or carriage height by adjusting the elevation of the guide hood, so as to obtain smaller air resistance.