Case size diameter: 41 millimeters, thickness: 11 millimeters Men's Mechanical Watch: Self-winding automatic movement. Powered by everyday movement of your arm Skeleton Watches: open dial, exposed movement, show the beauty of mechanical work luminous hands (need to absorb light energy storage) Waterproof watch: it's waterproof at 30 meters, and can withstand rainwater splash, rather than hot water shower and sauna