Anti-reflection coating on inner surface. Three-fold clasp with push button release. +5 to -3 seconds per day (under a static use) Note: This accuracy is the result of measuring the loss/gain of the time for seventeen days before the inside movements of the watch are put in the case. The measurement has been done in the factory where temperatures or position of the movements are controlled. When the watch is actually worn, the accuracy should be from +10 second/day to -1 seconds/day.Diameter 40.0mm Thickness 14.0mm. Screw see-through case back with sapphire crystal GMT hand Number of jewels: 37. Grand Seiko SBGJ021 135th Anniversary Hi-Beat GMT" is in sale since Sunday, March 31, 2019. This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Wristwatches". The seller is "philly-watches" and is located in Philadelphia, Pennsylvania. This item can be shipped to United States.