If you have ever bought a secondhand guitar with a Floyd Rose tremolo unit, it is reasonably likely that there will be a degree of play in the bar. People try various methods to shim the bar with PTFE tape or some other material, but it is far better to fix the problem properly by replacing the bar assembly with this item.
Basically you whip out the bridge unit, use a spanner to remove the bar holder assembly, and replace with this one. Job done! You may even find that this arm fits into your exising holder, in which case you don't need to replace the whole assembly.
Some licenced floyds may have unusual sizing but this defnintely fits Floyd Rose brand bridges.
You can usually be confident of good engineering with Schaller, and that is the case here.