A handgun having a frame with a barrel. In an embodiment, a technique may include receiving a plurality of video streams from a plurality of video sources in a room. Certain embodiments of the invention include a door assembly, which controls consumer access to product located behind the door assembly, a stop for limiting the forward progression of the pusher along the track, and mechanisms for generating data relating to when andor for how long the door assembly is open. A module for comparing the structures taking into consideration the identification marks and path information, is provided, for determining the differences of the structures. If a keyboard-video-mouse environment exists, each device in the plurality of devices is configured to the available state.