This option allows printing on both sides of a page. This unit supports A4, A5, JIS B5, Letter, Legal, Executive, Folio and Statement sizes. Paper (16 to 47 lb., 60 to 176 gsm) and card stock may be used with this unit. Product Type: Auto Duplexing Product Type: Auto Duplexing Compatibility: Lexmark T650N Printer Manufacturer Part Number: 30G0806 Media Size: Statement Media Size: Folio Media Size: Executive Media Size: Legal Media Size: Letter Media Size: B5 (JIS) Media Size: A5 Media Size: A4 Manufacturer: Lexmark International, Inc Product Name: 250 Sheet Auto Duplex Unit For T650N Printer Brand Name: Lexmark Brand Name: Lexmark Media Type: Card Stock Media Type: Plain Paper