1.2.1-20.1 is a release file of the Minecraft mod MekaGenJei (Mekanism Generator addon) for Forge, NeoForge, made for Minecraft 1.20.1. It was published on May 22, 2026 and is 0 MB in size. For the full description, screenshots and every other version, visit the MekaGenJei (Mekanism Generator addon) mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.