Squirrelly 4" to 3 inch 3-Ply 45 Degree Elbow Silicone Reducer Coupler Turbo Intake Pipe Black Squirrelly's line of silicone couplers feature 3 layers of polyester reinforcement and are suitable for applications with boost pressures up to 45psi. They also feature a temperature rating of 428F for direct to turbocharger installations. Size: 4" to 3" Length: 3.5" Material: 3-ply Polyester Reinforced Temp: 428 Degrees F (220 C)