JDM Sport - 2.5" Inch to 4" Inch Straight Reducer Silicone Coupler Universal Performance Hose Black/Red Triple Reinforced Silicone able to withstand high heat and pressure. Will Reduce Vibration transfer due to hard impact shifting or engine movements Can be use with Air Intake, Intercooler, Turbo Supercharger Applications Reduce the chance of charge pipe blow out by reducing movement. Can withstand 50+ PSI This is for the Coupler Universal ONLY