We just started chastity play a few weeks ago, initially purchased a couple cheap Chinese cages to get our feet wet - settled on a Jail House that 'seemed' to fit well.
Overall length including ring (measured centerline along curve): 85mm / 3-1/2" w/ a 35mm i.d.
https://www.amazon.com/gp/product/B01I0 ... =UTF8&th=1
First week wore it for a few days, second week was for 6 days, this past Tuesday I had been in for a solid week when decided to take it off as it seemed I was getting 'puffy' on the underside of my head - had what I assume was a pretty bad case if edema on the underside of my head, behind and off to the right of my frenulum, and a quarter sized area on my shaft a little further down. Took the cage off in the morning, by afternoon things looked better but still noticeable - 24hrs later it's cleared up quite well, I can see some 'slight' noticeable areas but only because I'm looking closely.
My Dims (flaccid - BTW, I'm cut):
Length (measure top of shaft): 4" / 101.6mm
Glans Dia & left over foreskin: 1.5" / 38.1mm
Shaft diameter: 1.25" / 31.75mm
I started out with the 45mm ring but found it would slip down during the day while moving around.
Moved to the 40mm ring - balls first and have to really squish my head and shaft hard to get thru; initially felt quite tight but got used to it very quickly - no color problems or apparent blood flow concerns. Typical night time burning from erections but that lessened quite a bit after a few days.
While wearing the cage I noticed I seemed to be ever so slightly kept a bit aroused and pushing up against the bars along my entire shaft (go figure...), on Monday before taking off I was having trouble with my skin pushing thru the bars ALL the time in the area where I had excess skin behind the frenulum - also during this period some evenings my wife would enjoy teasing me to watch me strain against the cage - I LOVED this also

We're both VERY adventurous behind closed doors and even though just beginning we both seemed to really enjoy this new dynamic so far - sincerely hope we can figure this out.
Even went so far as to ordering a Red Chili Tarantula over the weekend only to cancel on Tuesday morning upon discovering the edema and apparent cage size problem - I had used this cheap cage to match dims for the Tarantula - Aken was quick to refund; hopefully I can figure this out and re-order.
So...
Is it probably a case of too small a diameter?
The 40mm ring is tight but does seem too tight as blood flow seems fine and I can just get a finger underneath - I do compress the skin with the finger test if that's relevant.
Too much too soon regarding amount of time in the cage?
My thought now is to try a middle of the road cage to help nail down the size needed and leaning towards the S/S Spiral from UberKinky - small size which is 100mm overall w/ a cage dia of 39mm.
http://www.uberkinky.co.uk/spiral-stain ... 92662.html
suggestions?
Both my Wife/KH and I really want to figure this out - sorry for the long post.
Thanks,
Steve