This unit supports A4, A5 (long edge first), Folio, Letter, Legal and Oficio sizes. Only Paper (16 to 36 lb., 60 to 135 gsm) may be used from this unit. Install below any other trays. Paper size, paper and tray-present and tray-low and tray-empty sensing are supported. If the product configuration contains the 2,100-Sheet Tray, the optional caster base is required. The Spacer cannot be used with the 2,100-Sheet Tray.