BMW 4 Series F82/83 M4 Coupe/Convertible & M4 Competition Coupé (Non-OPF equipped models only)2014 Large-bore Downpipe and De-cat Fits with Milltek Sport cat back exhaust system only - Requires 2 x 18307851168 for installation (available from local BMW dealer) Tip Style: Pipe Diamater Inches:3