This is the hose that returns warm coolant from the automatic transmission oil cooler (heat exchanger) back to the radiator on N20/N26 engines with automatic transmission in the F22 228i, F30 320i/328i, F32 428i, X1 28i, and Z4 28i.
This is a Genuine BMW coolant line with a two year warranty. Buying a Genuine part will usually be more expensive than an OEM or aftermarket brand but you are assured that it meets BMW's designs for fitment, performance, and longevity. It will also be the very latest design, incorporating any updates or revisions that an aftermarket brand typically will ignore.
BMW Fitments:
2 Series
F22 / F23 (2014-2021) > 228i
F22 / F23 (2014-2021) > 228i xDrive
3 Series
F30 / F31 / F34 (2012-2019) > 320i
F30 / F31 / F34 (2012-2019) > 320i xDrive
F30 / F31 / F34 (2012-2019) > 328i
F30 / F31 / F34 (2012-2019) > 328i xDrive
4 Series
F32 / F33 / F36 (14-20) > 428i
F32 / F33 / F36 (14-20) > 428i xDrive
X1 Series
E84 X1 (2013-2015) > X1 28i
Z Series
E89 Z4 (2009-2016) > Z4 sDrive28i