"Waterproof Cooling Fan" in addition to a motor inside the base outside, the following are covered with dense air inlet hole, draw here is the most primitive part of the air. Blade less fan out of the wind box section below blade less fan base is covered with dense after air inlet holes into the base, driven by a motor, and then through the "Waterproof Cooling Fan" at the top of the base layer of hidden fan blowing upwards. This layer is horizontally rotating blades, installed after the wind outside the box can not see. "Waterproof Cooling Fan" outlet box and contact bayonet base motor and blades after the role has a certain flow of air into the interior cavity of the air box. Attention, inside the wind box is a special cavity structure, rather than a simple metal solid box.