An assembly of two components configured to be in contact with hydrocarbons, and a fuel tank including the assembly. The method continues by loading node definition data in response to the request, the node definition data defining the selected node of the virtual tree structure and how the node is displayed. Action mechanisms each having a hammer felt for striking a corresponding sounding member are disposed below the tone generator unit. The improved metric correlation analysis techniques allow users to more easily identify whether degradation in the performance of one metric is caused by performance degradation of underlying information technology system components as measured by related metrics specified in the metric dependency model. A history of previous searches is maintained in memory \u201cstacked\u201d notionally to the left or right of the current display so that a viewer can easily review previous search results using a simple scroll command. The substrate has a second substrate having a second face region.