Below is information direct from Germany regarding this product.
It may show additional information about fitment and specification.
Downpipe Kit with 300CPSI Racing catalyst for Audi S4 B9 / S5 F5 3,0TFSI
made out of high quality stainless steel 1.4301 (SS304)
complete 2x Ø3 and adapter for stock exhaust
CAD designed and flow optimized
300CPSI with EU6 coating Racing Metal Catalytic Converter
100% perfect fit, replace OEM
less thermal load on the turbocharger
more power by reducing back pressure
significantly more torque
optionally also available with Ø76mm (3 inch) middle silencer-replacement pipes (sporty, dull sound)
Error display in the DME possible.