The mechanical water pump on the S55 turbo 6-cylinder engine is essentially a wear item. With enough miles, stress, and age/time, eventually the water pump will fail and create a coolant leak or engine overheating situation that will leave your F87 M2 Competition, F80 M3, or F82 M4 broken down. And with cooling requirements on the S55 (turbos, intercoolers, transmission, etc) the water pump is tasked with more cooling demands than other designs.
This is a Genuine BMW S55 water pump 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.
F87 (2016-2021) > M2 CS Racing
F87 (2016-2021) > M2 Competition S55 (2019+)
F80 (2015-2018) > M3 (2015-2018)
F82 / F83 (2015-2020) > M4 (2015-2020)
F82 / F83 (2015-2020) > M4 GT4
F82 / F83 (2015-2020) > M4 GTS