MAZDASPEED3 Gen1 SS 3" Cat-Back ExhaustMFG# 571100 DESCRIPTION The COBB Tuning Gen1 MAZDASPEED3 Cat Back is constructed purely from 304 Stainless Steel. The system starts with a stock donut style flange that mounts to the OEM downpipe or any stock replacement downpipe, such as the COBB Tuning 3" Downpipe. Next up is a polished resonator section with attractive rolled end cap, followed by a polished low restriction straight through muffler section, also with this attractive rolled end caps.