The Simpson Duravent Elbow Direct Vent is a galvanized 45-degree elbow designed for HVAC and refrigeration systems. With a 4" ID and 6-5/8" OD, this accessory is perfect for connecting various components in your heating and cooling system. Made by Simpson Dura-Vent, a trusted brand in the industry, you can rely on the quality and durability of this product for efficient and reliable ventilation.