- Vibrant flexible couplings are engineered to isolate vibration generated by your vehicle's engine, thereby relieving stress on the exhaust system.- Flex couplings reduce premature cracking of manifolds and downpipes and help extend the life of other components.- TurboFlex couplings feature an internal stainless steel interlock liner that facilitates smooth flow of high temperature exhaust gases. These flex are for high performance (especially forced induction) applications