There are considered to be 5 main dial configurations...
Classic 3H/T - This has a red 3H-symbol that appears just below the dial center, and a tiny “T” that appears just above “6”
3H-only - A red 3H-symbol that appears just below the center.
T-only - Look for a tiny “T” that appears just above “6”.
Clean - No markings beyond the “Heuer” logo.
Sternzeit - Text with STERNZEIT REGULIERT markings just below the dial center.
As ever is all about the detail and some dials like the Sternzert are just rare so are priced accordingly.
Let me know if you need any further help.
Kind regards
The Captain