| Yes its a shorter bar than standard to allow you to lower the bike. I think the standard adjuster is on its lowest setting as it comes from the factory. So to lower the height you need the new adjuster. As has been said if you lower the rear by much you will also need to do the same to the front to preserve the handling. Problem is on the Multi is ground clearance especially with the exhaust shield on righthanders. I'm a good bit over 6ft and pretty heavy and the shield touches down easily at standard settings.
The Multis pretty tall but at 6ft I'm surprise you are struggling with the seat height. May I be so bold as to suggest a pair of 1970s Platform sole boots? You could then purchase a few Slade and Sweet and other glam rock records to go with the transformation. | 
Threaded Mode