The exhaust system pipe is made of high quality stainless steel. TECHNICAL PARAMETERS: - Angle: 90 degrees, - Diameter: 2.5 ", - Length: 61 cm, - Material: Stainless Steel. There are also available for elbows: Stainless steel pipes. exhaust made of high quality stainless steel. TECHNICAL PARAMETERS: - Angle: 90 degrees, - Diameter: 2.5 ", - Length: 61 cm, - Material: Stainless Steel.