This is a nice example of the Optimus 550 and it's original box. This was bought together with a Primus 1550 (can be found here) and I believe left the Optimus factory at the same time as well. It has an identical stamp on the box flap as the Primus lantern (251369), which would indicate that several models and both Optimus and Primus left the factory at the same time.
