Diversified Imports Tunnel Shutters are designed to reduce high energy costs and eliminate the operating issues associated with curtains and door systems in poultry houses and hog and dairy barns. Tunnel Shutters have an airtight pressure seal and utilize the negative air pressure within the house as opposed to doors that constantly fight against the static pressure. When closed, the shutters create a 2 inch thick insulated solid wall. Tunnel Shutters can be utilized in all climates for both indoor and outdoor applications, with or without doghouses.