I found this little tool in a metal box that contained Singer sewing machine accessories. But, this small box and its contents were out of a larger cardboard box that also some watchmakers tools. I can't seem to figure out if this goes with the sewing machine accessories or the watchmaker tools. Hopefully someone out there will recognize this thing and let me know what it does. Thanks.

Bruce

I am going to guess it is for adjusting watch bands, JB Champion was or perhaps is a watch band company.

Tom

You're correct Tom.
Brian C.

Tom and Brian, thanks for your help in identifying this thing.

Bruce,
The part with the fractions on it, fits in-between the lugs to tell you the width of the band.
Brian C.