How to enlarge the selection circle of an item?

[Mashira]

I can't see any option that relates to that other than "Art - Scaling Value" which enlarges the item model, or anything similar to the "Selection Scale" like you have when customizing units.
Do I need to edit the model itself or something?

Any help is greatly appreciated!

 

[Kino]

The 'Art - Scaling Value' determines the size of the selection, you have to edit the model itself to change it.

Item selection scale...