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 2100-Sheet Tray.