Ford Focus ST Mk3 Cobra cat back system - Non resonatedPart number: FD46 This Cobra Sport exhaust is made with T304 grade stainless steel, mandrel bent and Tig welded which will allow a smooth flow to maximize power gains. These parts are made in 3" 76. 2mm pipework and fit from the catalytic converter section backwards (Cat Back) these parts replace the centre and rear sections. This non resonated system makes the system louder as it excludes the centre silencer and therefore, has a sportier exhaust