Shell Properties assigns a wall thickness to an activebody, making it hollow, thus making the shellable
volumes in the body hollow.
Each solid functional set may contain a single shell property feature
that specifies the thickness of the walls globally for the solid functional
set. This thickness is then used by functional features that produce walls. The
shell properties are also used to define the open faces of the resulting shape.
Other Offset Faces Options
You can specify different wall thicknesses for each face using the
Other Offset Faces tab.
Faces box under Other Thickness Faces lets you
manage the selected additional faces and their individual thicknesses.
If
you select several features, the box displays the number of selected
elements. To act on this selection, click to
display the panel that allows you to:
View the selected elements and specify individual thickness values.
Remove any element.
Apply thickness to all selected faces:
Applies the thickness value specified in the
Thickness box to all selected faces.
Core Tab
The options available in the Core tab, let you manage the shell update.
It displays the list of shellable features and how each contributes to the shape of
the shell. In case of an update error in the shell property, you can quickly
identify which shellable features caused the error, activate or deactivate shellable features, change their core
contribution type, and try another update.
There are three types of core definitions for a shellable feature:
Interconnected core: The union of the
interconnected shellable features is the main input of the shell property
feature that computes either the inner or the outer shape for this union.
Faces causing trouble with Interconnected Core option in
Shell Properties
Isolated core: The offset is computed
separately for the shellable features using this option. The faces of features
that have an isolated core cannot be later selected in the
Shell Properties dialog box as
Face to remove or
Face with special thickness.
Select core: You can select a separate body
that defines the inner or outer shape of this shellable feature.
The Shell Properties using Selected Core with Core
Display Only Parents option can be used while editing a functional
feature. It is mainly useful for local modifiers such as drafts, chamfers, and
fillets features that use face or edge selections.
It displays the minimum creation context of the feature being edited, by deactivating the
feature and all the features which are not parents from it.
to
display the panel that allows you to: 
