Abstract: Vertical suspension legs are clamped to a margin of a desk top. The suspension legs support a tray at a plurality of selectable vertical levels. There is a connection station on each vertical leg corresponding to each of the vertical levels. The tray has engagement devices for engaging the connection stations corresponding to any selected vertical level. Each connection station can be a plurality of detents which mate with a corresponding plurality of tangs projecting from a side of the tray. The plurality of tangs engaging a corresponding plurality of detents prevents rotation of the tray about the connection points. The stations can also be laterally open horizontal open slots defined by the vertical legs which mate with side rails projecting from the tray. Slidingly extending through the vertical legs are vertical shanks, the top ends of which are connected to an elongated crossbar.