TEM DESCRIPTION: HP LaserJet 4250 & 4350 Series Duplexer model Q2439b. Comes in lightly used, working condition. Ready to install & use. HP Part #: R73-5047 Also enables duplex printing for 4200 and 4300 series printers: 4200 4250 4200n 4250n 4200tn 4250dt 4200dtn 4250dtn 4300 4350n 4300tn 4300dtn 4350dtn 4300d Please verify printer compatibility with hp.com. No additional driver is needed, but printer drivers can be downloaded online