This is a replacement media sensor for Datamax printers.  They list for $500-$600 and suppliers are frequently backordered.  Snag this as a spare unit, cheap, while you can get it!

Honeywell - A-CLASS, MEDIA SENSOR ACCESSORY

Compatibility:

Datamax A-Class Printers:

  • A-4212 Mark II
  • A-4310 Mark II
  • A-4408 Mark II
  • A-4606 Mark II
  • A-6212 Mark II
  • A-6310 Mark II