Resizing Issues


Hello, I’m new at Zapworks and I couldn’t find this answer here at the forum.

I’m working with eyeglasses (.OBJ) and the object keeps resizing from face to face, as it’s a try on of a real object I need it to have a fix measure.
The properties shows the option scale to fit, but it’s impossible to uncheck this box.
How do I keep the ratio and not scale to fit?

Tks for the help