The function of this ventilator is to keep the inside and outside prsssure to be balanceable , even if the inside temperature is below 0℃, so as to ensure free opening of the door .

With a temperature controller inside the window , which keep the window’s temperature within 20℃-40℃, then guarantee fluent ventilation .

With a stainless steel mesh , which prevent the insect from entering .

Groove on the vents , avoid the inleakage of water.

AC 220V or AC 110V are on your option .