We've put this kit together to allow us to keep our NC EFR Turbo Kit a full 3" downpipe without requiring you to run a custom exhaust. This setup adapts from 3" to 2.5" to render your factory mid-pipe compatible. You'll simply cut your OE mid pipe and use the slip joint included. Additionally, when you're ready to run a custom 3" exhaust you can simply trim this adapter before the reduction for a nice clean 3" v-band installation.