The height adjustable Fellowes Office Suites Underdesk Keyboard Drawer converts a conventional desk to an ergonomic workstation! Moves keyboard and mouse off the desktop to save workspace. Unit is easy to install and offers three different height adjustments to suit preferred work position. Mouse tray dimensions = 7.25" x 7.5" and comes installed on right side of keyboard tray and stows underneath keyboard tray when not in use. Requires 23.5" of width and 14.5" of depth underneath your desk for proper installation. Obstruction free area required: Ensure the installation area is free of any obstructions, such as crossbars or supports, that may interfere with mounting the hardware. Spacious platform accommodates keyboards up to 20" wide and 7 5/8" deep. Installation requires mounting to the underside of a desk using Philips Rounded Head Screws #7, ¾” Long.