Grand Seiko Spring Drive chronometer wristwatch. Model reference SBGC203. Stainless steel case in a 43.5 mm diameter with "Zaratsu" and "Hairline" polish finish. Black dial with highly polished finish appliques. Calibre 9R86 Spring Drive chronograph movement with an approximate power reserve of 72 hours. Sapphire crystal glass and exhibiton caseback. Watch recently fully serviced ex-Japan. All links included. Comes together with original box, paperwork and service records. THis was the first ever Grand Seiko chronograph, this model is powered by a Grand Seiko's unique Spring Drive calibre, which combines the motive force of a mainspring with the high precision of a quartz watch. The Spring Drive mechanism allows the watch to maintain precise timekeeping while also incorporating accurate chronograph capabilities,The chronograph utilizes a Ready/Start button with a half-press shutter, reducing mistakes and allowing for accurate starts. The button produces a satisfying click with just the right resistance. '