Hiss Ventilation Device

It is suitable for windows that can be pulled horizontally or pushed or fixed, for walls made of aluminum or glass, etc. The internal switch and feathering paddles can both control the ventilation effect. Based on the principle of air convection, the device can be assembled either on the top side or upper side of the glass. It is very safe and easy to assemble. Even when the windows/doors are closed, the air is still ventilated, with anti- theft function; no additional electric power is needed. As a result, staying home in the winter can be very joyful.