Silicone Hose (Angled Elbow Coupler). 1x 2.5" to 2" silicone 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.