Hello, I'm not sure if you remember or not, but we all decided that a 45mm ring was my best size for me (and my device) a week ago. I'm no longer sure about my ring size due to a couple of symptoms I am feeling and I might go back to a 50mm. There are several reason on why. First off, the type of ring for my new device is not an oval or an arc-base ring but a plain circle, so everything is 45mm all-around. I would like to know what are the advantages and disadvantages are when it comes to plain rings versus oval rings and if size plays a big difference between the two types of rings. 1.) After measuring it multiples times, the diameter of my base where the ring goes is around 55-50mm with the tightest hard pressure. Does 5mm less make a difference in tightness and difficulty putting it on? 2.) With the 45mm ring, I can feel my second testicle cramp when I pop it through. After it pops through, it is very difficult to push my fully flaccid penis (no excitement) inside the ring as I have to pinch it and pull it through. Ouch. The same difficult apply when taking it off as I have to push the penis out and I can feel my testicles get pushed as I pull it out. This never happens with the 50mm. With the 50mm ring, every goes in so easily (but too easily). When do I have the 50mm on, I can tell it could be a much tighter when flaccid. Maybe this pain is normal. 3.) When the 45mm is on and I am semi-erect, I cannot even fit a lubed cotton swab inside the ring unless I push the ring downward into the scrotum, apply the lube on the area, and push the ring back. The pressure is too tight when erect, which makes some sense on why I had a rash. The 50mm ring causes a different type of rash from rubbing back and forth when walking but it is not that bad if I apply lube overnight as the rubbing stops when laying down. 4.) One final thing: I noticed that there is a gland/bump in the perineum (muscle between the rectum and penis) that enlarges before right the bladder needs emptying while erect. This bump is located where where the ring would be as if is was fully fit to the body. As a result, it gave me an unbearable pain when I had the 45mm ring fully fit to the body overnight without the device on. I do not believe it is an infection but something to do with the bladder or prostate. I am going to try to do it again with a 50mm ring (when I get one) to see if it just because the ring is too tight. I am the only one who notices this gland? So, I am sure that 50mm might be too big but I now believe that 45mm is too tight. Is there a 47mm ring? Nope. I hope to hear some feedback soon. Have a great day.