The feature Shell
Step by step that we have to do is:
Step I: Open shell_face_selection part.
Step II: Run the Modeling application.
Step III: Create a shell feature.
Select the icon Shell.
Insert> Offset / Scale> Shell
Fill in the desired thickness
Choose five face to be deleted: front, back, left, right, and bottom
Select OK.
Step IV: Edit feature Shell.
Work Area direct view to Front.
MB3> Orient View> Front
To Fit the view
MB3> Fit
Choose Edit> Features> Edit Parameters.
Select the feature Shell and OK.
Change the thickness and select OK two times to update the model.
Note the offset of material in the opposite direction.
Step V: Close the part.