Exterior Exterior: 18K pink gold case Back: 18K pink gold and sapphire glass Back Cover Specification: See-through screw back Glass Material: Box-shaped sapphire Coating: Internal anti-reflective coating Case size: 38.0 mm (width), 44.7 mm (height), 12.9 mm (thickness) Band Width: 20mm Band Material: Crocodile Movement Movement: 9S85 Instructions Driving System: Mechanical, self-winding (with manual winding) Duration: Approx. 55 hours at maximum winding Static Accuracy: +5 sec. to -3 sec. per day on average Accuracy measured under the conditions of 6 different positions and 3 different temperatures before shipment from the factory in accordance with Grand Seiko's own standards. It differs from the accuracy (portable accuracy) under the environment in which the watch is actually used by the customer. Also, due to the characteristics of mechanical models, depending on the conditions of use (carrying time, temperature, arm movement, strong shocks or vibrations), the accuracy may exceed the aforementioned range. Portable accuracy: +8 to -1 sec. per day Functions Water resistance: 10 atmospheres Anti-Magnetic: Yes Other: Yes Screw lock crown Lock: 18K pink gold Number of jewels: 37