Balastit
Balastit is a term that appears to be a misspelling or a non-standard term. It is possible the user intended to refer to "ballast," which has several meanings depending on the context.
In electrical engineering, ballast refers to a component in a lighting circuit that limits current. For example,
In maritime contexts, ballast is material carried in a ship's hull to improve its stability and reduce
In the context of railways, ballast refers to the crushed stone or gravel that forms the bed
If "balastit" refers to something else, further clarification would be needed to provide an accurate description.