It is a prime tower.
It helps to maintain a clean and colour-pure model.
You can enable or disable it, change the location, and change the size.
When you have colour changes in a single layer, it is far more useful.
Your model only changes colour at each layer, by the looks of it, you could disable it and your model will look just as good.
If you wish to move it, simply drag the rectangular block when in the preview tab.
If you wish to change the size, use the values in the “others” tab.
