Scene Scale ImagePreset (dropdown): Select a unit conversion type for the scale percentage. The current presets are: mm to cm, mm to in, cm to mm, cm to in, in to mm, in to cm.
Scale %: The scale percentage. Disabled when a preset is chosen.
Selection Only: Operate on only the selected objects. When disabled will operate on all scene objects.
Freeze Scale: Resets the scales of the objects to reflect the scaling applied.
Rescale Scene: Executes the script and scale the scene/objects.