What does the “ E/U “ mean ?

Seen at https://armysurpluswarehouse.com/signal-generator-ts-452-e-u/

for $249, brand new, BUT….it looks pretty HEAVY, for sure.

You may want to waste some moments looking at this site, https://armysurpluswarehouse.com/

They still do have Army headphones Vietnam era NIB for $5.

-Hue Miller