Compact 1x1 loader requiring electricity to run. There are options to enable or modify capabilities like stacking, disable power consumption, or recipe cost.
This only applies to 5Dim recipes that 5Dim adds. The base game has no recipe for loaders.
It is controlled by a mod setting. You can choose to keep the 5Dim loaders if you wish. They are redundant and less capable (no stacking, no split lanes). But if you want to continue to use / keep them change the mod setting to keep 5Dim's loaders.