This 4 Inch Pellet Chimney Stainless Steel 90 Degree Elbow from the PelletVent Pro series is a Type B gas component and consists of the duralock system for a tight seal. Offsets obstructions as needed. Elbows swivel 360° at base. Angle is not adjustable.Elbow by Angle: 90 (degree) Finish: Stainless Steel Fuel Type: BioFuel, Oil, Pellet Material: Galvalume, Stainless Steel Pipe Class: Type L Pipe Inside Diameter: 4 Pipe Shape: Round Style: Contemporary Modern UL Listed: Yes Vent Construction: Double Wall Weight: 2