Grand Seiko's first mechanical complication combines a constant-force mechanism and a tourbillon as one unit on a single axis. | Grand Seiko,Shinko Tires - 777 Front Tire 130/90-16,Shinko SR777 Rear Motorcycle Tire 130/90-16,S1 Rally model 28290 | InvictaWatch.com,The Shinola Runabout 25mm,