The patent pending EcoTight Shutter will significantly improve your fan efficiency and prevent cold air leakage. Manufactured to your desired custom size, the EcoTight Shutter is made of heavy-duty, durable twin wall profile frame for longer life and stability. Its aerodynamic design allows for maximum air performance while minimizing light into animal room. A key feature of the EcoTight Shutter include side profile with individual patented Eco Adapter Blade Clips designed to allow for expansion and contraction while reducing air leakage and light. No blade flip-over or blades getting stuck in the open position. Each blade pivots on a continuous fiber rod. Excellent cleanability with durability to withstand pressure washing.