NOS M-250A's Nameplate

"JU" is stamped on there very lightly in red ink (pink, really) but it's not visible in the pic. The box was also stamped JU (which means September 1982 BTW) and the capacitor is dated to 1982.

You can see the nameplate says the voltage is 120/240, suggesting it's a multi-volt ballast. However, the way you can tell it's not multivolt by just looking at this tag is that there is only one rating for line amps. Also, if it was 120 and 240V, GE would have marked the voltage as 120X240V rather than 120/240V. Subtle, yes, but that's how they did it!