There is NO bolt in converter for the 1999 to 2005 Mazda Miata. Instead, on the 99-05 Miata the catalytic converter is a welded-in part of the exhaust midpipe (California 99-00 Miatas also have second converter in the header assembly). This is the best Miata performance midpipe available for the second generation Mazda Miata and includes a highflow converter and built in resonator! Full 2.5 inches from tip to tip in all stainless steel. ALL the Mazda Miata mufflers we sell for 99-05 include just the muffler and not a midpipe (unlike the 90-97 choices). Therefore, if you want the flow to connect your new high flow Miata performance header to your new high flow Miata muffler, here it is. Great for any normally aspirated or supercharged or turbo Miata. All stainless steel parts means years of quality miata performance. Not CARB approved. Has factory location O2 connection...and optional use extra connection in the cat for EGT. YES, fits anywhere your factory 99-05 Miata midpipe fits!