Mesh Part Settings
Under a Mesh Part node you add nodes for importing and modifying an externally generated mesh.
The Settings window for a Mesh Part node contains the following section:
Units
Mesh files are unitless, which means that the physical size of an imported mesh is independent of the length unit of the mesh part. Select the Use units check box to use the length unit and angular unit (which you specify using the Length unit list and Angular unit list, respectively) in the nodes appearing under the Mesh Part node.
If the mesh part and the component referring to the mesh part have different unit systems, the resulting geometry is scaled.