Exterior: 18K yellow gold Case back: 18K yellow gold + sapphire glass Back lid specifications: See-through screw back Glass material: dual curve sapphire Coating: Internal anti-reflective coating Case size: Width 39.0mm Height 44.0mm Thickness 11.6mm Band width: 19mm Band material: crocodile Movement: 9S63 Instructions Drive system: Mechanical hand-wound Driving period: Lasts approximately 72 hours (approximately 3 days) at maximum winding Static accuracy: average daily difference +5 seconds to -3 seconds Accuracy is based on Grand Seiko's own standards when measuring the movement as a single unit before shipment from the factory under conditions of 6 position differences and 3 temperature differences. Accuracy under the environment in which the customer will actually use the product (mobile accuracy) differs. Also, due to the characteristics of mechanical models, the accuracy range described above may be exceeded depending on the conditions of use (time of use, temperature, arm movements, strong shocks or vibrations). Mobile accuracy: +10~-1 seconds per day Waterproof: Waterproof for daily life Antimagnetic: Yes Weight: 85.5g others: Number of stones: 33 stones With small second hand Power reserve display function