Use to offset obstructions as needed. Fully unitized, twist-lock construction. Elbows swivel, allowing the lock to remain fully engaged while aligning to the desired direction. The angle will remain fixed at 90°.ADA Compliant: No Elbow by Angle: 90 (degree) Finish: Painted Black Fuel Type: Gas, Liquid Propane Material: Aluminum, Galvanized Steel Pipe Class: Direct Vent Pipe Inside Diameter: 4 x 6-5 8 Pipe Shape: Round Style: Contemporary Modern UL Listed: Yes Vent Construction: Double Wall Weight: 3