Squirrelly 3.5" to 3.0 inch Silicone Coupler Straight Reducer Hose Intercooler Piping 3-Ply (Black) Squirrelly's line of silicone couplers feature 3 layers of polyester reinforcement and are suitable for applications with boost pressures up to 45psi. Size: 3.5" to 3" Length: 3" Material: 3-ply Polyester Reinforced Temp: 428 Degrees F (220 C)