That’s a great looking cage but smaller is better, I think, as in...as small as you can possibly manage in a safe, sane way. That said, I really do think a lot of people inclined this way go through some trial and error. They DO have to make a first purchase that will require them downsizing, a LOT more often than the other way around. Pretty sure you’d want a device to only just barely accommodate your totally flaccid penis...nothing more. That may leave room for interpretation, but surely the point is to leave as little wiggle room/growth opportunity as possible.
I’ve seen guides that recommend subtracting
at least a quarter to half an inch from your absolute smallest flaccid length to reckon the desired fit. Some indicate an entire inch may be preferable. That pretty clearly suggests you should completely fill up the tube/cage both girth and length-wise...and do so while limp. That means touching the end AND touching the sides. Contact all around. You don’t want to cut off circulation, obviously, but one can safely compress a soft dick some
every which way, especially length-wise, without doing
anything close to that.
The Ring-While it needs to be snug as well, it’s probably more critical to take care that the ring(the part of the device encompassing your whole package...balls AND penis together) not restrict blood flow, cause numbness, etc. You absolutely want to surround and confine your penis though, thwart arousal/erection. You want to be packed neatly—not crammed— into a device.
And then the games can begin😉
