Tailor’s tape and string have been responsible for millions of dollars of cages that wind up in the trash or at the bottom of a drawer. Worse yet are the folk that give up on chastity completely because the cage doesn’t fit right after all their hard work and diligence of sizing.

Mature Metal realized early on in 2009 that the community needed a way of sizing that was easy to use and could be relied upon to give the wearer the best chance of getting the sizes right the first time. You no longer have to spend a fortune on cages that didn’t fit right before finding the right sizes. Keep in mind that comfort is all about the fit.

The plastic ring sizing kit will help to walk you through the four sizes needed to complete your order: cage diameter, base ring diameter, length, and gap. If you still have questions once you receive the kit you can still email maturemetalsales@gmail.com or call with any questions. We are always here to help. Your questions are so important to us that you will be answered by either Mistress MM or William, the owners of Mature Metal.

What’s in the Kit, and Why It Works

Nine rings covering 1 1/8″ to 2 1/8″ (28.6 to 54.0 mm), made in the same thickness as the rings on our custom devices, so what you feel in plastic is what you’ll feel in steel. The plastic rings are round. You will have the option of ordering the oval base ring, but rest assured that the oval rings will have the exact same inside diameter as the round. The reason is that we start with the ring that you order in round, then make it slightly oval so that the ring is wider than it is tall.

Instructions: it is a single sheet of straightforward help that took many years to develop. We have been making cages since 2009 and have helped thousands of clients with the fit of their devices. Like in most things, the process is easy when you know what you are doing. There is a reason why Mature Metal has a reputation for having the most comfortable cages and best customer service on the planet. We truly care about our clients and that they can wear their cage in comfort and security.

The Rules for Sizing

1. Always measure alone. Your Keyholder should not be in the room when measuring. You must be at your normal flaccid state for the test to be accurate. If you are not, then you will get bad results.
2. Never measure after just getting out of the shower. Again, if the shower was hot or cold then you will not be at your normal flaccid state.
3. Only have one ring on at a time. Do not test with the base ring test ring and the cage ring test ring at the same time. They are two different tests.
4. Lay out the set of rings. The rings are not numbered, so lay them out smallest to biggest. This way when you select a ring you can compare it to the instructions to get the proper size of the ring.

How to Test

1. Base ring. Put on the rings starting with the largest. You will put one testicle in at a time, then tuck in the penis — so yes, this is the ring that goes behind the testicles. It may help to put a drop of baby oil to get the ring on. You may need to wait until you are at your normal flaccid state before going to the next step. Try watching TV or doing something boring, as that seems to help. Then see how many fingers you can get under the top of the ring up to the first knuckle. You should be able to only get one in (you should not have to force your finger in). If you can get two fingers in, then the ring may be one size too big, so try the next size smaller. Continue with this process until you are comfortable with the results. You want the ring to be tight enough to hold up the cage but loose enough to allow blood flow. If you get an erection during this process, the ring will work as a cock ring. It will most likely hurt, so try to stay calm and not get aroused. Keep in mind that when you have the cage attached to the ring, it will not allow you to get an erection, as the cage will hold it back. It should not hurt at that time; you should just feel pressure.
2. Cage diameter. Start with a ring that you feel will fit you best. Put the ring on the shaft, then again do anything to get your mind off of it. If you know how to knit, that may help. Then just look down. The right size ring should just indent the skin. If you see extra space between the skin and the ring, then the ring is too big. This is the most important size, as the inside diameter can never be adjusted. You would have to purchase a new cage if it is the wrong size.
3. Length. For the length you will need a hard ruler. Make sure you are at your normal flaccid state. Place the ruler under the penis, just touching the scrotum. Do not push in, then measure out to the tip. Do this test several times at different times of the day. Again, never out of the shower. Then take the shortest measurement and subtract 1/4″. This will be the cage length. The cage length does not include the ring or the gap. It is only the length of the cage, measured down the inside center of the cage.
4. Gap. There is no good way of measuring the gap, other than if you know that your scrotum is high and tight, or maybe you have had other cages where you always have a burning sensation in the scrotum, then you may need the 1/2″ gap. If the gap is still too small, not to worry: since all cages are handmade, the gap can be made any size if needed.

   If you are more normal and haven’t had any issues with burning from other cages, then I would suggest the 3/8″ gap. The 3/8″ fits most of my clients.

   Lastly, if your scrotum hangs low then you may need the 1/4″ gap. Also, if your cages have been sliding down, then you may also need a double base ring.

   When measuring a gap on a cage, some manufacturers measure from the bottom of the back of the cage to the bottom of the base ring. With this method the gap will always change with the ring size or shape of the ring. I measure the gap straight across from the bottom of the cage to the side of the base ring. This way the gap will stay consistent no matter the size or shape of the ring.

Exceptions to the Rules

The rings aren’t big enough. This is very rare, but there are those out there. Please contact us — we can help with that.

In between ring sizes, or custom sizes. We can do any size cages or rings. Just be aware that there may be an upcharge depending on what is needed. Just contact us.

Thank you for considering Mature Metal. If you still have any questions, please let us know.

Thank You!!! Mistress MM and William

One safety note from the same people who wrote the rules above: any numbness, coldness, or change of color during a ring test (or in any device, ever) means it comes off immediately. Snug is the goal; numb is a stop sign. (This is general information, not medical advice.)

Sizing-Ring Questions, Answered

How do you use chastity sizing rings? Lay the nine unnumbered rings out smallest to largest, then run two separate tests: the base ring test (largest first, one testicle at a time, one finger to the first knuckle under the top of the ring) and the cage diameter test (best guess on the shaft; the right ring just indents the skin). Never both at once, always alone, never fresh from a shower.

Which of the four sizes matters most? The cage’s inside diameter: it can never be adjusted, so a wrong number means purchasing a new cage. The gap, by contrast, can be made any size and adjusted afterward, because every cage is handmade.

What if I’m between ring sizes, or off the kit’s range? Any size cage or ring can be made — in-between sizes included — with a possible upcharge depending on what’s needed. The kit not reaching your size is rare but real; email maturemetalsales@gmail.com or call, and Mistress MM or William will sort it out with you personally.

Are the sizing rings oval? No, round — and that fully sizes an oval order. The oval base ring has the exact same inside diameter as the round: the round ring you order is made first, then shaped slightly oval so it’s wider than it is tall.

Note for build: mark the block above up as FAQPage schema.

Got Your Number?

Then the hard part is over. Browse the full range and order with your four sizes, or send your results to the workshop first for a second pair of eyes. And if the kit isn’t home yet: plastic sizing rings, instructions included, measurements you can actually trust. The full sizing story lives in the complete sizing guide.