A:Answer Thank you for your interest! The tray is mounted to the underside of the desk using four adjustable brackets. It requires 23.5" of width and 14.5" of depth underneath your desk for proper installation so an obstruction free area is required. You will want to ensure the area is free of any obstructions, such as crossbars or supports, that may interfere with mounting the hardware. We suggest visiting our website for additional information: https://www.fellowes.com/us/en/catalog/details/US-9140303
