Black 45 Degree Elbow Silicone Hose Pipe Intercooler Coupler Turbo 2" 4Ply. Silicone Hose (Angled Elbow Coupler). Elbow Angle. Silicone + Polyester. 4-Ply Silicone + 3-Ply Polyester Reinforced. Silicone is resistant to electrochemical degradation, however, are not suitable for use with oil or fuel.