And, it looks like a 40mm or so watch. How old is it? What do the RR and numbers signify? Is Wittnauer still making watches? As an aside, when I was a kid Longines and Wittnauer seemed to be mentioned in the same breath when they sponsored a radio or tv program. And, they only sponsored the classiest programs such as opera or orchestra concerts. Also, any indication that your model watch was also issued to railroad employees? I bet collecting Railroad Approved watches is an entire segment of watch collecting in itself as with Military Watches.