This is the second time I've owned this eyepiece, having sold it once a year and 1/2 ago and just gotten it back in a trade about a month ago from the same guy. I was told when I originally bought it about 3 years ago that it is a Nikon Orthostar, and it does fit that description. but I want to describe it and you decide for yourself.
It is perfect, has a brushed aluminum barrel with knurled ring where it meets the upper barrel like the old Meade Research grade eyepieces. The black upper assembly is chamfered to a flat top measuring about 1/2" across with the small eyelens in the center. The side of the chamfered surface reads only "6.6mm". There are no other markings. The inside of the aluminum lower barrel is grooved and flat black. There are no baffles. The top of the eyelens has a small amount of smudging, probably from eyelashes, and would easily clean. There is not a box, but I do have caps for it. As to performance, I have not reused it since reacquiring it, but last time around it was my pride and joy in that focal range. I have now built up a set of Taks and Pentax, but am not sure they exceed the performance of this eyepiece. I think it is as good as my Taks, but not quite as good as the Pentax. I need a 6mm Pentax ortho to complete my set
I am frankly not certain what this eyepiece is worth and would like to just ask for offers. I would also discuss trades for other, high quality eyepieces or what-have-you.