These are heavy duty 2U shelves that fit any standard 19" rack. Used for non-rackable equipment, monitors, printers, a keyboard and mouse pad, or a workspace, a couple of these are a necessity in almost any rack installation. They are screwed down on one side only and support an incredible amount of weight.
They are 14.5" depth, so in most full racks, they can be installed offset on both front and back allowing you to take advantage of space that might otherwise go to waste. I often install one in the top 2U's for network equipment, one at arm height as a workspace, and then as needed for other equipment.
I have seven to sell. Width of the actual shelf is 17 1/4". From ear to ear, they are 18 3/4".
I also have some slide out 1U railed shelves/trays (they can be either trays or shelves depending on whether you install them upside up or upside down). And will be listing a gorgeous full size rack with a smoke glass door in a couple days. See "More ads by this user" link for other items.