This is the largest downpipe on the market with a smooth transition from 4.5" to 5" to 4" to the OEM connection of 3.3"

Nearly all the downpipes on the market neck down quickly to 3" right the start of the flex joint. The most important section of the exhaust is right after the turbo & why we now have what you see here.

Features

Full Stainless Steel 304, Stainless Steel flex joint with an inner Stainless liner inside for durability, longevity,

What you'll notice is a much deeper exhaust note, better spool/response. 

This item fits the following BMWs:

2016+ F20/F21 F22/F23 BMW M140i, M240i & M240i xDrive

2016+ F30 BMW 340i

2016+ F32 440i