When my wife agreed to locking me up and to go with the chastity lifestyle we ordered the HT right away. But I found that I didn't want to wait that long to get started, so ordered device #1 the day after ordering the HT.
CB-4000 It arrived in the mail on Monday. The velvet bag was marked CB-4000. Of course the CB-X folks don't make a 4000 or any devices like this. The only ring available is 45mm, which I thought should be OK since that is what I measured for the HT. Not. The ring is very fat, and it was a very tight fit. The fun came trying to fit it over an engorged penis, while holding the ring closed. I ended up using a stocking, holding the thing closed, fitting the two together etc. etc. But I fit it on. But the blue balls did not come from denial... I quickly discovered that the cage was HUGE. I have quite a variety of underwear, (my wife would call it a fetish), but even so it took quite a few tries to find something that would hold it all. Still, not very noticeable under my jeans.
Material - black chrome plated metal. I don't think it's stainless steel
Comfort - none really. If I could find a 50mm ring I might try it again.
Long term wear - I wouldn't, After 2 days I was looking to get relief from the tight fit.
So I ordered another after rooting around quite a bit more.
Cost - around $30 with shipping
Update: This device is now in a landfill somewhere. Really unwearable and it was taking up space in the drawer.
Jail House M200 Ordered this from Amazon. By the time the gift card and all that were applied, out of pocket was about $10. I can live with that. An improvement on the 4000. It came with three rings - 40mm, 45mm, 50mm. didn't even try the small one, and went for the 45. Comfort was better. I found that squeezing my nuts and cock through the ring was a little mind bending. Lubrication, either lotion or oil was necessary for the last bit. I also needed the stocking to pull through. Poked myself several timed with the pins, but got locked in. Slept through the night with it on. Went out of Friday evening, and found that the square end of the back end of the locking pin was poking into my abdomen. Saturday ground it round, polished, buffed and replated with rhodium (no chrome on hand) Better. But it was still rather tight, so I tried the 50mm. Balls popped out three times - back to the 45mm. Saturday afternoon the shaft of my cock looked healthy. Sunday afternoon it was in sad shape. Actually went to bed with no cage. No worry about masturbating - it was too sore. Off and on wear through Thursday.. Monday I ordered #3.
Material - I think it's stainless. Non-magnetic white metal, fairly hard, with an under layer plating of copper and a top layer of chrome. Had to use a polishing wheel to smooth out the welds and replate.
Comfort - 3/5 Not a hopeless case. I still may use it later on. The problem is that the ring is too tight. I don't know what caused the irritation of the top of the shaft of my cock, but it wasn't pretty. Now healed, but it took 3 days.
Long term wear - Might work for some, but not for me. At least not yet.
Update - I find that I'm in this one again, and actually comfortable. Once I adapted to wearing a chastity device, the ring works fine. The only drawback is that the end of the cage leaves the glans unprotected, and there is occasionally some pain as it brushes against my underwear (soft nylon) if at all engorged. But I'm wearing it now.
Bon4M - large This is the last one, and the best so far. I like the look of this one the best. It fits in any of my underwear, it's discrete, fairly comfortable. The cage is cast stainless, finished out the outside and given a brushed stainless finish. No plating. The inside is pretty much the natural matte finish from the casting process. Not rough, but not shiny smooth either. I took some time to use a fine abrasive wheel on the edges of the holes and as much as possible to the inside. I may post pictures in another post of the before and after, since I've reached my limit here. I rounded off the corers of the ring, and put a thin PVC tube over the hinge of the ring. It's nice - I fill the cage completely most of the time. Engorged, I get a nice snug feel, no pain from the holes. I'm using the 48mm ring, and find it to be about ideal. I like being able to clean well, and use Burts Bees Mama Oil to lubricate so that things don't bind. I find that I really want to keep this one on, though it will take some getting used to. Having half a pound of metal hanging off of your nuts takes a little getting used to.
This one is the most comfortable of the three, and the least noticeable. The pin does dig into the abdomen a bit when I sit in the car, but that's about it. I like the fact that once you close the ring, you can put the locking pin through to hold it closed while you fiddle with the cage. Much easier to put on. I still use the stocking to pull myself in. Use care in lining up the pins on the cage. Very secure once locked. I like the look and feel of this one.
Material - 304 stainless steel
Comfort - for now a 4/5
Long term wear - likely. I'm still waiting for the Holy Trainer to arrive, but I like the idea of a more open cage that can be cleaned easily in the shower.
Note that with all three of these, I didn't really try to get out. First, the reason for going into chastity is to stop masturbating. Second, my wife agreed, so I want to honor that by not working to get out. But the truth is that I rather treasure my "family jewels" and am allergic to pain. I might be able to get out, but at what cost. With the fit of the first two, I know I'd never get out anyway without serious pain. See previous comment.

I have tried urinating while standing in the B4M only. With the first two it was obvious that I'd spray everything around me, and maybe hit the target on occasion, so I didn't even try. Even in the B4M I tried it in the bathroom with the tile floor, pants well in the clear. The big hole in the end helps, but I still prefer to sit. It's safer.
The interesting thing is that with the Jail House and the B4m, I've been sleeping through the night, when I usually didn't before. Maybe it's my brain relaxing, knowing that masturbating isn't an option, so why get up other than to drain the bladder. Tight, maybe a bit of a pinch with the B4M, but nothing serious. Feels nice, and I feel myself swelling as I think about it.
Update - I keep trying it, but keep going to something else after a day or so. I've tried all kinds of things with this one. The big issue is the unfinished interior. I've used a polishing stone and fine wire wheel, but that isn't enough. A bit sore last night after 48 hours of wear, so I took it off to check. I found cuts from the edge of the bar, that I thought I had smoothed enough, on the underside of the shaft. Clearly from the edge of the bar from the location and the spacing. I think I will need to buy a shorter one, and maybe shorten the spacing pins and therefore make a new locking pin before it will work. But that is on hold until I can insure that the cage can be made smooth enough that it won't cause harm.
Maybe a Mature Metal device someday, but right now other life expenses get priority,