This Subaru BRZ (ZD8) performance exhaust is made in 2.5"/63.5mm pipework and fits from the secondary catalytic converter section backwards (cat-back) this exhaust replaces the centre and rear sections.The resonated exhaust option includes the centre silencer and has a subtle but sporty tone. This exhaust however, is also available as a non-resonated version (excluding the centre silencer) which is a louder option as it excludes the centre silencer and therefore, has a sportier exhaust note.Cobra Sport performance exhausts enhance the sound, looks and quality of your vehicle giving you the ultimate driving experience.Cat/GPF-Back (Resonated) Test Results:Sound - Engine at Idle: 60.9dB (+6.3dB) - Static 4,000rpm test: 83.6dB (+6.6dB)Cat/GPF-Back (Non-Resonated) Test Results:Sound - Engine at Idle: 61.5dB (+6.9dB) - Static 4,000rpm test: 88dB (+11dB)All relevant fittings and gaskets are supplied.