It could represent a version like v1.7.3 with a "2x" modifier (possibly referring to a 2x speed mod, 2x texture pack, or a secondary revision).

The "2x" suffix is frequently used in community-made patches for games to denote "Double Resolution" or "Double Rate" (e.g., Nexus Mods often hosts such files). Safety and Handling

any reason to prefer WinRAR/WinZIP to 7-Zip? - Windows