Convenient mounting for monitor and one keyboard. Mounting hardware not included. The keyboard tray extends 8.6" (218 mm). 19"W rack trays must use small footprint keyboard; maximum width 16.30" (414 mm). 19" holds equipment up to 17.75"W x 19.8"D (450.9 mm x 503.4 mm), 23" holds equipment up to 21.75"W x 19.8"D (552.5 mm x 503.4 mm). Made of strong, lightweight aluminum; supports up to 200 lb (90.7 kg).