Collector Transitions are swedged tapered cones that enhance exhaust scavenging from a Merge Collector outlet (throat) and enable the use of a larger exhaust pipe and/or tailpipe size. Most Transitions are available in .065 & .049 material thickness.Collector transitions are available in 3, 7, & 13 degree tapers. SPD can also finish a Collector Transition to a T03, T04, or T100 rectangular Turbo inlet to fit most turbo applications. Buy the best in Collector Transitions at SPD.