Squirrelly 3" to 4 inch 90 Degree Elbow Black Silicone Coupler Reducer Pipe Hose Finish up your custom piping with one of our silicone couplers. Use for air intakes, intercooler piping, turbo inlet/outlets and more. Squirrelly's line of silicone couplers feature 3 layers of polyester reinforcement and are suitable for applications with boost pressures up to 45psi. Leg Length: 3.5" Temp: 428 Degrees F (220 C) Size: 4" to 3" reducer