HP JetDirect EX Plus J2591A.  Ethernet print server for parallel port printer.

I used this for many years with an old HP laserjet printer.  It always worked well.  

Includes Jetdirect box, printer cable (DB25 to Centronics), and original HP power supply.

I don't have a printer to test it with now, but it turns on and the lights blink.  I was working well when I put it away a few years ago.