Opis_1.2.1.zip is a release file of the Minecraft mod Opis, made for Minecraft 1.6.4. It was published on April 7, 2014 and is 9.3 MB in size. For the full description, screenshots and every other version, visit the Opis mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
