This is the upgraded 220A alternator from the dual climate control model. Its actually 220A vs 180A standard. Its also cheaper than the 180A. 

Genuine Valeo 220A BMW E70 alternator

Suits M57N2 only. 

Does NOT suit M57N

OE PN 12317801124 12317804266 12317804266

Valeo PN 439606

About Valeo

Valeo is one of the world's largest Tier 1 OEM (original equipment manufacturer) suppliers to the automotive market because of the high quality and wide depth of expertise, spanning powertrain systems, thermal systems, comfort systems and visibility systems. In fact, Valeo is the number one supplier of OEM wiper blades and wiper systems in the world. The same high quality OEM parts are available for aftermarket replacement, so you know you will get superb quality, fit and finish in easy-to-install components.