Awning rail measurement for Astrodome/Astroflyte??

[LittleVintageTrailer]

Anyone that owns either a Astrodome or Astroflyte, can you tell me the exact measurement of your awning rail (where the awning attaches)? I'd measure my own but it won't be here until next week and would like to get an awning ordered so we can have it done and here in a couple weeks. I just need the exact
measurements in inches across that awning railing where it attaches to the trailer.

Thanks!

Kelle