By sensing an object without performing light projection with a light projection unit, a first image is acquired, and by sensing the object while performing light projection with the light projection unit, a second image is acquired. The assembly includes a sealing portion including radially inwardly directed teeth, and a dovetail mounting portion including a hollowed out portion including a biasing member internal to the packing ring segment. A graphics device may generate a composite notification message based at least in part on the notification messages from the primary and the secondary notification modules, where representations of the notification messages are stacked one on-top of the other in the composite notification message.