Case: 18K White Gold Back: 18K white gold + sapphire glass Back cover specification: transparent screw back cover Glass Material: Box Sapphire Coating: no reflective coating on the inside Case size: 40.0mm wide, 47.4mm high, 12.1mm thick Strap width: 19 mm Magnetic buckle: one key double opening mode Movement model: 9RA2 Driving mode: spring driven automatic winding (with manual winding function) Driving time: about 120 hours (about 5 days) at the maximum winding Accuracy: mean monthly difference ± 10 seconds (equivalent to daily difference ± 0.5 seconds) Waterproof: reinforced waterproof for daily use (10 air pressure) Diamagnetism: Yes Other: Power reserve display function