They were originally designed by ITT but the ITT design used thread on optics which was not ideal. ITT was LE only.
Back in the day Gale McMillan told me he created the VisionsMaster series of these with a 2-10x56mm and 6-16-80mm model which used the quick connect pin (major improvement) out of frustration with ITT policies.. I am not sure if he was working with Seiler Instruments on these.
Over the years I had two of the VisionMaster 2-10x56mm units and one of the 6-16x80mm units. I have said in past write ups it was a love hate thing. All of mine had exposed turrets which I did not like, but the main problem in my opinion was that the crosshairs were to thin. When looking into dark areas it was hard to make out the crosshairs. Most times the design also required the introduction of additional IR illumination which was not really a problem. In fact the eye shine made it easier to kill the predators. The 6-16x80mm unit was a boat anchor and I hated it. Each time I sold a 2-10 I regretted it.
Seiler continued making these and they were rebranded as the Aurora. They are no longer on the Seiler site so I think production is done from them.
I have no knowledge about the 830 model that THEIS mentioned above.
ATN made a similar unit and as I understand it it had an illuminated reticle, not sure if it was NV compatible.
As we know Clip-Ons became all the rage but I think these scopes are still cool and if someone would have made some additional improvements, like a thicker reticle or an illuminated NV compatible reticle or dot it would have made the scope so much better.
The last few I saw go were in the $2k-3k range. Someone has a couple of the older ITT units up on ebay for what I think is to high of a price.