The WS08-CP-V2 is a 3 inch High Flow Catalytic Converter designed specifically for your 2008-2014 Subaru WRX and STi. It has a 100cpi metal substate catalytic converter. Please note that this part is NOT a stock replacement pipe. This part requires that you already have the front half of a TurboXS downpipe (part number WS-DP-V2) to make a complete downpipe that will mate from the turbocharger outlet to a catback exhaust. If you already own a TurboXS downpipe with racepipe (part number WS08-DP) then you can use this pipe to convert your catless downpipe WS08-DP into the catted downpipe WS08-DPC.