DuraVent 3145B 4PVL-E45B Black Stainless Steel 45 Degree Elbow. DuraVent is a leader in the venting industry. DuraVent has a large line up of venting products and continues to design safe and efficient venting part and products. This DuraVent 3145B 4PVL-E45B Black Stainless Steel 45 Degree Elbow is designed for a venting system designed for stoves and inserts that use wood pellets and oil fuel. This high quality Elbow is ideal for both indoor and outdoor vent applications.