[QUOTE="Higgins"] Having taken the 9-5 Aero headlamps apart, to modify them for driving on the mainland, I can confirm that you are correct. There is a shaped shutter which cuts off part of the beam and a little solenoid moves it out of the way when main beam is activated.[/QUOTE] Seems like a sensible system. I stared down the barrel of the 911 lights last night. Dip is an HID projector unit. Main is another bulb unit below. It *looks* like a conventional bulb but it's a similar colour to the dip. I shall have a look under the hood this weekend. I rode home in the dark again last night, one almost doesn't need the high beam, so good is dip but it does add in some range.