Factorio 2.1 compatible stand-in for "UltimateBeltsSpaceAge" 1.3.0, which only supports 2.0. Same entities, items, technologies and settings, so saves keep everything. Disable the original while using this. Once the original supports 2.1: enable it and disable this mod (this mod also goes inactive on its own when the original is loaded).
Mods introducing new content into the game.