Our 5" Heat Shielded Super Sports Cat made to fit the legendary BMW B58 features a new Euro 6 standard catalyst. This pipe is massive, the 5" tube that gradually steps into the 4" flexi pipe is the biggest pipe combination available on the market today for the B58, this ensures maximum, uninterrupted flow to match that of a full decat downpipe so there is no longer a compromise on power when choosing a sports cat.