As discussed in Surface-to-Surface Contact (Pair-Based) it is paramount that the contact elements be oriented correctly for proper contact detection. The contact manager provides tools that help you
Verify that the normals of the contact and target surfaces are in the correct direction
Reverse normals of elements that are not oriented correctly
You can choose to display one or more contact pairs on which to perform the above listed operations. Then you have an additional option of only displaying the contact surface or the target surface when verifying or reversing the element normals. In addition these elements can be displayed independently or in the context of your entire model. In the later case the contact elements are highlighted in a translucent plot of your model.
Another important function is to edit the properties of the contact pair(s) as needed. The properties include real constant values and key option values as discussed earlier. The button in the contact manager provides a simple to use interface that allows the properties of the selected contact pair(s) to be reviewed and modified if needed.
Note that when you have multiple contact pairs, it is possible to have conflicts in the real constant values or in the KEYOPT settings. When you have such conflicts, the properties dialog for those real constants or KEYOPT settings is left blank.
Finally, you can display or list specific contact result items (contact status, penetration, pressure, etc.) for the selected contact pairs. This option is only available in POST1, and only if a result set is available. The contact results can be displayed independently or in the context of your entire model. (For CONTA175, results can be listed but not displayed graphically.)