Squirrelly 4" to 4 inch Silicone Straight Hose Coupler Turbo Pipe Intercooler Piping 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. Material: 3-ply Polyester Reinforced Temp: 428 Degrees F (220 C) Length: 3"