Since we've had some issues recently with fitment for this downpipe, we recommend a different downpipe: 
Click here for Evolution M 200 cell
Click here for Aulitzky/HJS 200 cell with TÜV 

**We strongly advise replacing the gasket and clamps when you replace your downpipe, ensuring a perfect fit and seal. We have this kit available here: https://autotopnl.shop/products/b58-gasket-clamps 

With the larger cells and fast exhaust flow rate, it is smooth, durable and does not have refractory wool burn-out problems. The higher the number of the cells, the smaller and denser the hole is. The higher the back pressure, the more it can enhance torque performance, while the opposite is true for increasing horsepower. Converting your stock catalyst converter (400~800 CPSI) into our metallic catalyst converters will result in significant enhancements in airflow discharge that circumvents the limitations and parameters set by car manufacturers.

Fits:

BMW M340i (G20/G21) 
BMW M440i (G22/G23/G26)
BMW 540i (G30/G31)
BMW 640i (G32)
BMW 740i (G11/G12)
BMW 840i (G14/G15/G16)
BMW Z4 M40i (G29)
Toyota Supra (A90)