Comparing Dimensions to the CB6000s

I currently own a CB6000s and am prepared to buy a Jailbird from Mature Metal. I’m curious if anyone has upgraded this way before, specifically regarding whether they could reuse the CB6000s measurements for their Jailbird purchase. My current setup uses a 1 3/4” Ring with a 3/8” gap (though I can accommodate a 1/4” gap), and my length fills about 2 1/2” of the device, leaving just 2” at my smallest size, along with a 1 3/8” Cage Diameter. My main question is whether there’s a noticeable difference when switching to the Jailbird or if these measurements hold up well enough. I have a steel cock ring measuring 1 3/4”, which allows me to pass both balls through it comfortably so I can sleep without issue. While I could fit the CB’s 1 5/8” ring, I noticed more discoloration and doubt whether my balls would pass through a fixed ring of that size on the Jailbird.

I’d appreciate any advice since I’m eager to buy soon. Mature Metal’s fitting guide suggests most users go with a 3/8” gap, which might differ from my current setup due to cage design variations; perhaps I could use the 1/4” gap with the CB device instead.

It’s essentially the same thing but different. Check out the MM website for their measuring recommendations; I strongly suggest using their guide when placing your order. When I received my first MM device, it was too long. I had filled the CB6000s to its limit and assumed that length was what I needed, even though the MM measurement guide advised getting one 1/4" shorter. My subsequent MM device ended up being shorter. I’d recommend starting with a 3/8" gap. I made this same mistake initially. Because I hang lower, I could wear my CB setup using just the KSD as a spacer (about 1/16") and ordered an MM device with a 1/4" gap. Within thirty minutes, I realized something was off. Looking closer at the CB device explained why. The MM device is very solid thanks to its screw mechanism, leaving no room for movement. In contrast, the CB device moves significantly in a vertical direction. When measuring, I found that the bottom gap of the CB could change by almost 1/2".

I believe with a 1 3/4 oval ring (Oval is essential in my opinion) to prevent testes from slipping through and a 1 3/8 cage, you might have blood flow issues... A 3/8 gap should help. I personally prefer the 1/4 gap. I use a 1 7/8 ring with a 1/4 gap; my 1 3/8 cage fits snugly without any circulation problems. For cage length, I’d suggest taking an average between the shortest cold measurement and normal. If your CB6000s diameter fits well without forcing it in (using a Q-tip as reference), you might consider going down by 1/8 inch because of the Jail Bird's open design. I can only speak for the 1/4 gap configuration, but based on your post, I’d say the smallest setup would be a 1 3/4 base ring with a 1/4 gap and a 1 1/4 diameter cage. For me personally, I need about a 1/2 inch difference between the cage diameter and the base ring diameter when using a 1/4 gap. Hope this helps... all4one

Hi, I have a similar question. I’ve worked my way down to using the 1 3/4" A-ring on the Cb-6000s along with the smallest (1/4") spacer. With the next larger spacer size up, I started experiencing ball slippage issues, though only one testicle slips because it is slightly smaller than the other. It can be tight at times but remains manageable. Now my wife and I are considering getting a Jail Bird or Queen's Keep. I've read that Thumper suggests going down one ring size on metal devices compared to the CB; my concern is whether there will be enough space if I downgrade to a 1 5/8" ring while keeping the 1/4" gap, and also whether choosing an oval ring might compound this issue. Any suggestions? Thanks!