Exterior: 18K pink gold Back: 18K pink gold and sapphire glass Back Cover Specifications: See-through screw back Glass Material: Box-shaped sapphire Coating: Internal anti-reflective coating Case size: 36.5 mm (width), 42.7 mm (height), 11.7 mm (thickness) Band Width: 18mm Band Material: Crocodile Caliber No.: 9S64 Instructions Driving System: Mechanical Hand-wound Duration: Approx. 72 hours (approx. 3 days) at maximum winding Static Accuracy: +5 seconds to -3 seconds per day on average Accuracy measured under the condition of the movement as a single unit before shipment from the factory under 6 different positions and 3 different temperatures, based on 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: +10 to -1 sec. per day Water resistance: 10 atmospheres Magnetic resistance: Yes Weight: 80 g Other: 18K pink gold Lock: 18K pink gold Number of jewels: 24