Grand Seiko Spring Drive Chronograph SBGC203 

The Grand Seiko SBGC003 Spring Drive Chronograph GMT is an example of one of the most difficult timepieces to build at Seiko's Shinshu Watch Studio, in the Nagano prefecture of Japan.  The 416 part 9R86 caliber found in the SBGC003 is all constructed by hand, by only 3 craftsmen at Shinshu Watch Studio.  Only capable of building 2-3 movements per day, the 9R86 contains over 50 jewels, 140 oil points, and 5 different lubricants all made in-house by Seiko.  The SBGC003 also utilizes a vertical clutch and column wheel, allowing for a more precise and durable usage of the chronograph.  The Grand Seiko SBGC003 Spring Drive Chronograph, once only availbale in Japan, is now available in the USA with gorgeous black matte lacquer dial and stainless steel case and bracelet.

Drive system Spring Drive
Caliber No. 9R86
Case Stainless steel
Case back See-through screw case back with sapphire crystal
Glass High definition dual-curved sapphire crystal with anti-reflective coating
Bracelet Solid stainless steel
Buckle Stainless steel with three-fold clasp with push button release
Accuracy ±1 second / day
Water resistance 10 bar
Magnetic resistance 4800 A/m (60 gauss)
Weight 187g
Case thickness 16.1mm
Case diameter 43.5mm
Jewels 50
Remarks 
Blue-steel center chronograph second hand, Blue-steel chronograph minute hand, Blue-steel chronograph hour hand
Screw crown and screw buttons