All our watches is perfect same like genuine spec. For example Rolex Submariner Date 126610 model, technically our watches is perfect same like genuine using Swiss Cal. 3235 movement spec engine. Functional of the watch is exactly same like genuine, power reserve is 72hr, 28,800 bph and hairspring is blue parachrom. Base on this condition, this kind of watches is so good for daily rugged use or alternative use with your authentic watches.