This attribute can be used at the assembly level. Typically the attribute constructors take two types. The two types are a visualizer and a visualizer object source, specified as types or as fully qualified assembly type names. The second option is provided so that the visualizer assembly does not need to be referenced by the assembly containing the System.Diagnostics.DebuggerVisualizerAttribute. This allows a component creator to ship the visualizer in a DLL to be called only at debug time. The DebuggerVisualizerAttribute.Description property specifies the visualizer description that appears in the drop-down box. The target parameters specify the type that is the target of the visualizer. For more information about visualizers, see Visualizers.