Follow-Up to my original post:
I did finally get the device and was able to successfully lock it on. Yay!
Overall, it's still a little heavy (though not nearly as unwieldy as my Mike's Spikes) and once on it's reasonably comfortable and enjoyable to wear. It's too big and sticks too far out to be practical under clothing, as my wife noted right away. I can also see why people go for a shorter cage length - though I would want a little more headspace.
It really does pinch! After some initial struggles, I got better at putting it on, which helped. I also added some A&D Ointment to the pinch points on the device, and on me, which also helped. But then during wear, there were more awkward moments.
The best part about it were the three ring sizes. I struggled to get in the largest at first, but then after 20 minutes it was slipping off. The medium was a better fit, though I could probably benefit from a millimeter or two less. Not sure I can take trying the small ring!
So it was worth $18 for the chastity experience and to get a better understanding of my various sizes. I'll try it some more and look out for an upgrade.
Amazon says the device is by Romi, but I didn't find any name on the cage or packaging.
Thanks, everyone for all the feedback and advice!
For the gearheads in the audience