The Insul-Ventilator is constructed as a one piece unit. Available in galvanized, aluminum, copper and stainless steel, it is a truly efficient, weatherproof ventilator. It is easy to install and offers an ideal solution to insulation efficiency loss and/or moisture-condensation problems. The Insul-Ventilator can be manufactured with insect screen or bird screen. Manual dampers or temperature controlled dampers are also available. 12" Throat. Stack Height: 12.