The Secret Key To Chastity Device Fitting

I get several emails every week about fitting problems with chastity devices. The most frequent question is about comfortably wearing the base ring. That’s the ring that you put your balls and penis through. It anchors the chastity device. These complaints fall into two categories: the ring hurts all the time, and when the penis tries to get hard the base ring slips up the penis and “strangles” the balls. There are endless forum and blog posts about these issues. Even though they cause a lot of discomfort, base ring fitting is not the most critical measurement.

Much more important is how the cage itself fits. I think that almost every guy wearing a chastity device has a poorly-sized penis cage (or tube).  I’ve noticed that Mature Metal, makers of the Jail Bird chastity device has noticed this too and has revised their fitting instructions. Most guys end up with cages that are too long for them. The reason isn’t that they don’t measure correctly. It’s that while people say how a cage should fit (it should fit like a glove, always touching the sides and top of the cage), they don’t explain how to measure to get this result. Here is how I finally managed to get it right.

First of all, the flaccid (soft) penis is extremely flexible. You can see this for yourself. Take your soft penis and push it toward your body. If you’re soft, it will compress to half or less of its normal flaccid length. The same is true of the diameter. You can squeeze it without any pain to half its normal diameter. If you’ve checked yourself out at different times, you will see that the flaccid length varies at different times. It can shrink to a nub or hang down longer than usual. The diameter doesn’t generally change much unless you get hard.

The thing is that you can’t comfortably compress it much in both length and diameter at the same time. Also, reducing the diameter can restrict flow through your urethra. But compressing the length has no effect on that. Any custom cage you order wants to know the diameter of the cage and its length. If you lay your soft (make sure there is no arousal at all – soak it in ice water if needed) penis across a ruler, you will get an idea of your soft diameter. Don’t let the ruler support the weight, that will cause the diameter to expand. Do this at different times until you have several readings. Take the smallest one and subtract 1/4-inch (6 mm). That is the diameter of the cage to order.

Each chastity device maker has specific requirements in how you measure the length. If you can’t find that requirement on their website, email them for information. Mature metal wants measurements on the  underside of the penis from where the scrotum ends and the penis begins all the way to the tip of the head. Be very careful to get this accurately. Don’t press the ruler into the scrotum and be sure you are fully soft. Take several measurements at different times.

Everyone gives you that advice. Many, including Mature Metal tell you to subtract 1/4-inch (12 mm) and use that as the length to order. I found that to be completely wrong. The cage that was based on this measurement almost never touched the head of my penis. Remember, we want full contact all the time. We measured the gap when the head was furthest from the end of the cage. It was about 1/2″ (12 mm) too long. I had it shortened by 1/2″ and it fits perfectly. My suggestion is to subtract 3/4-inch (18 mm) from the measured length of your penis and order that as your cage length.

In my case, I measured 2-inches (50mm) as my flaccid length. My original cage was 1 3/4-inches (44 mm) long. I had it shortened to 1 1/4-inches (31 mm). It looked too short to ever fit me. The first few days were a little uncomfortable. It felt like my penis was jammed into the cage. I even had “grill marks” on the head from when I tried to get hard inside it. After about three days I forgot the cage was there. I could pee comfortably and the urethra usually was nicely centered so no spray when peeing. When I attempted to get hard, nothing moved. The fits-like-a-glove cage kept everything in check.

The secret is to accurately measure both diameter and length. I ordered diameter 1/4-inch less than what I measured and length 3/4-inch less. My very comfortable cage is 1 1/4-inches diameter (I measured 1 1/2″) and the length is 1 1/4-inches long (I measured 2-inches). Your results may vary. Penises are highly individual.


  1. Author

    I have just an added tip or two, for those considering devices solely secured by a piercing (especially a PA), but with no testicle ring at all. These would include the Lori devices, the PA-5000, the MouseTrap, and some Steelwerks units.

    For this type of device, the diameter is critical, and it’s probably smaller than you think. For example, I’m of average, or or perhaps a bit larger, size, but I’ve settled on a 1″ OR 1-1/16″ tube for the Lori devices.

    Lion’s measurement method should work pretty well, especially for the lighter units. For the heavier Lori devices, taking off another 1/8″ to 1/4″ of diameter seems to help, since the friction of the device on the shaft supports all the weight. Ideally, the enclosed portion of the tube nestles directly behind the corona for support, but if the diameter is too large, the head will slip in also and let the tube rest on the piercing.

    Ah yes, the piercing. Despite its intimidating appearance, I really feel that the PA is much superior to a frenum piercing for chastity purposes. First, it’s a very easy piercing to get, and it heals rapidly and with little risk of infection (being bathed in a sterile, mildly acidic wash several times each day). Also, the frenum piercing seems quite prone to migration and eventual loss, although I’ve heard that a second attempt is often successful due to the scar tissue left by the first try.

    The PA, though piercing quite a thin section of flesh, nonetheless encompasses a fairly large section, and so is reasonably robust. For the heavier Lori and Steelwerks devices, this is really necessary, and still requires a larger gauge piercing; a minimum of 4-gauge is essential, and 0-gauge (5/16″) seems to be about the ideal. For the much lighter PA-5000 and MouseTrap units, there isn’t such a tendency to slip down past that coronal ridge, so anything 8-gauge or larger is fine.

    Still it’s amazingly easy – and a considerable amount of fun – to stretch a PA piercing. Just wearing progressively heavier jewelry will stretch it with essentially no overt effort, and the dangling weight provides a nice ongoing titillation. (This, incidentally, is one of the reasons I like wearing a Lori tube, too – the frequent tug while I’m moving tends to keep me somewhat aroused, without being able to do anything about it, of course.) Also, in non-chastity applications, my wife quite likes the feel of a larger piece of jewelry inside her when have intercourse.

    The length of these devices is not too critical. The penis is almost never against the bars at the front (the PA-5000 and MouseTrap don’t even enclose the head at all). The tube just needs to be long enough to cover that “sweet spot” on the lower shaft – perhaps 1″ to 1-1/2″. Longer is fun, if ones flaccid penis will accommodate it, but it’s not really necessary and adds significant weight to the device.

    My wife can tease me *extremely* effectively just by playing with the exposed portion of my shaft; this has me going crazy in just a couple of minutes. It seems like my body just can’t realize that the stimulation won’t continue on up to the covered area, and keeps trying by thrashing and pumping. Speech, of course, is long gone at this point.

    1. Author

      I tried several Lori devices with my frenum piercing. All were so heavy that the piercing got sore and I had to remove the devices. Even if you “lock” the device on with a piercing, I prefer the cock and ball ring to take the weight of the piercing.

  2. Author

    I completely understand this sentiment, and actually I think that the Lori devices in particular are largely impractical with a frenum piercing. (Although, I just received a new one today, and she’s evidently using a somewhat thinner-walled tubing, so the weight is quite reasonable now.)

    I have quite an aversion to the trapped-ball devices, though. Firstly, I’ve found them to be complete insecure unless supplemented with a piercing (for which a frenum would be fine, since there’s no load).

    The big reason though is that, although there’s no way I could be considered to have an “active lifestyle”, I found that the constraints of the testicle ring just made day-to-day living too uncomfortable and inconvenient. Admittedly, my most recent device of this type was a CB-3000, and the state of the art may have advanced some since then.

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