Add up to 3 optional 550-sheet input paper trays and a 2100-sheet high-capacity feeder to allow a maximum of 4,400-sheet input paper handling. Upgrade output capacity to up to 2,050 sheets by adding the 1500-sheet stacker. Print on a variety of paper types including labels, envelopes, transparencies, heavy cardstock and perforated legal forms. Sort and stack printouts from different workgroups and facilitate document management with the optional 4-bin mailbox. The optional Staple Smart™ Finisher staples documents up to 50 sheets thick. Includes standard USB and gigabit Ethernet. Connect easily and print on fibre-channel networks by adding the optional Dell™ Fibre Interface Card Kit. An optional parallel, serial card kit and optional wireless server for 802.b/g/n wireless data transfer is also available5. Improve the performance and functionality with the optional Hard Disk with encryption to protect user data.