This hose runs from the left auxiliary radiator and feeds coolant to the main engine radiator in the front. While not a high wear item the hoses should be replaced with a new because old hose connections do not always re-seal well. This is a Genuine BMW hose with perfect fitment.
BMW Fitments:
3 Series
F80 (2015-2018) > M3 (2015-2018)
4 Series
F82 / F83 (2015-2020) > M4 (2015-2020)
F82 / F83 (2015-2020) > M4 GT4
F82 / F83 (2015-2020) > M4 GTS