This is the innermost, static part of the alternator which carries the windings, and has the wire to connect it to the main loom. This is a pattern item and the manufacturer says: 'manufactured using a high quality core and the highest grade copper wire for the windings. The reconfigured winding configuration from stock and the high magnetic conductivity of the new stator core result in vastly improved efficiency compared to stock.
This stator offers a beautiful flat power output across the RPM range and it also runs much cooler than the stock BMW stator, which drastically improves reliability. We install very high grade wires that feature heat and chafe resistant insulation and high quality rubber seals and insulation coatings, making this stator a plug in replacement of the BMW OEM unit.'