L: Lapped Seam S: Spot Welded B: Buffed Interior 7" to 24" Diameter 90° , 60° , 45° , 30 ° angles L-S-B Elbows are constructed of gores lapped over one another, spot welded and buffed smooth on interior. This is a directional elbow and supplied with an arrow to indicate direction of flow. LSB Elbows are available in Galvanized, Aluminum, and Stainless construction