This is a 140A Bosch Internal Fan Alternator for BMW 540, 740, 750, 840 and 850 Series. This Unit Has 3 Mounting Ears - at 1:00, 3:00 and 6:00 (Approx.). There is an Air Scoop Pointing Straight Down at 7:00. There is a 3-Prong Rectangular Plug on the Back at 1:00. The Terminals are "(D)-L-IG". This Unit Has a 7-Groove Serpentine Pulley. The Only Difference Between the Two OEM Numbers is That the Pulley May Vary, But They Transfer Between Units, if Necessary.