HP Duplexer C4083A is compatible in the following HP Models:

HP LaserJet Automatic Two-sided Printing Units

HP LASERJET REMARKETED DUPLEX UNIT - C4083AR

HP Color LaserJet Auto Two-sided Printing Units

HP COLOR LASERJET AUTO DUPLEX UNIT - C4083A

HP Color LaserJet 4000 Printer series

HP COLOR LASERJET 4500 PRINTER - C4084A
HP COLOR LASERJET 4500 REMARKETED PRINTER - C4084AR
HP COLOR LASERJET 4500DN PRINTER - C4094A
HP COLOR LASERJET 4500DN REMARKETED PRINTER - C4094AR
HP COLOR LASERJET 4500N PRINTER - C4089A
HP COLOR LASERJET 4500N REMARKETED PRINTER - C4089AR
HP COLOR LASERJET 4550 PRINTER - C7085A
HP COLOR LASERJET 4550 REMARKETED PRINTER - C7085AR
HP COLOR LASERJET 4550DN PRINTER - C7087A
HP COLOR LASERJET 4550DN REMARKETED PRINTER - C7087AR
HP COLOR LASERJET 4550HDN PLUS PRINTER - C9729A
HP COLOR LASERJET 4550HDN PRINTER - C7088A
HP COLOR LASERJET 4550HDN REMARKETED PRINTER - C7088AR
HP COLOR LASERJET 4550N PLUS PRINTER - C9727A
HP COLOR LASERJET 4550N PRINTER - C7086A
HP COLOR LASERJET 4550N REMARKETED PRINTER - C7086AR