Chastity cage buying guide — CB-6000, Cherry Keeper, Mature Metal, Holy Trainer

A chastity cage — the wearable device worn over the penis to prevent erection, used in chastity practice, where one partner's orgasms are controlled by the other — is, mechanically, a simple object. Sizing it is the entire game. The single largest predictor of whether a couple keeps their first cage past the second week is whether the cage fits, and we've yet to read a thread where the first cage fit because the wearer guessed at his measurements instead of taking them. This guide walks through what to measure, what to buy first (and what not to), and the small set of devices the threads actually settle on after the inevitable first false start.

Sizing: the load-bearing variable

A cage has two principal dimensions and a secondary one. The principal dimensions are the diameter of the base ring (which sits behind the testicles, around the base of the penis and scrotum) and the inner diameter of the cage tube. The secondary dimension is the length of the cage tube. Cage length is overrated by the marketing copy and underrated as a source of fit problems; the ring is what makes or breaks a cage.

The ring. The ring should sit snugly enough that it cannot slip forward over the testicles, and loose enough that no part of the genitals turns blue or numb when worn for hours. The right way to size a ring is with a length of soft string or a thin shoelace, not a guess. Loop the string behind the testicles and around the base of the shaft, in the position the ring will sit. Pull until snug but not tight. Mark the loop. Measure flat, in millimetres. Most adult men land between 40 and 52 mm; the most common sizes ordered are 45, 48, and 50 mm. Buy the cage with multiple ring sizes if the manufacturer offers it; many do. Measure when warm and at room temperature — sizing while cold after a shower will give a smaller number than the ring you actually want.

The tube diameter. The tube needs to accommodate the penis at flaccid state, with a small amount of room. Too tight and it pinches in any partial swelling; too loose and the device slides. Most adult men land between 32 and 40 mm of inner tube diameter at flaccid. The wider end of that range is more forgiving, especially for new wearers; the narrower end is for men who actually measure narrower at flaccid.

The tube length. A short cage (under 50 mm flaccid length) is more comfortable for many wearers and forces a slight retraction inside the cage; a long cage matches the flaccid length closely and feels less compressed. Both work. Longer is not better — many wearers report short cages are easier to wear all day and to sleep in. The tube length is a preference variable, not a fit variable; do not chase the longest cage available.

Hygiene access. The single most important practical feature, and the one new buyers underweight: how easy is it to clean the cage and the genitals while the device is on. Cages with wide ventilation slots, tubes that disassemble, and rings that disconnect from the tube without a key are the cages that survive past the first sweaty week. Cages that are one solid sealed piece — beautiful in photos — are the cages that come off after three days and never go back on.

Materials, briefly

Three materials cover most of what the threads use.

Plastic / polycarbonate. Cheap (€20–60), light, easy to clean, TSA-friendly for travel, and the standard starter material. The downside is durability — plastic cracks under sustained pressure, especially at the ring junction — and it can feel less real. Most plastic cages are generically interchangeable; the differences between brands are small. Plastic is right for the first month, while the wearer figures out whether the practice is one he wants to invest in.

Resin / 3D-printed bio-resin. The middle of the market in the last few years (€60–150). Lighter than steel, more durable than basic plastic, available in custom sizes, can be made in skin-tone colors that disappear under clothing. The Cherry Keeper is the canonical example. Many wearers settle here permanently and never feel the need to upgrade further.

Steel / titanium. The premium tier (€200–600+). Heavier, more secure-feeling, better-looking, will last indefinitely if the wearer's body doesn't change. Custom-fit steel from Mature Metal or Steelwerks is the gold standard the committed long-term wearer eventually arrives at. Steel cages are also the cages that occasionally complicate airport security and MRI scans (titanium is MRI-safe; many steels are not). The weight some wearers love and others find tiring.

Silicone. A small fourth category. Soft, forgiving, useful for long flights or for the first night a wearer is trying chastity at all. Silicone cages do not really prevent erection so much as discourage it; for a serious practice they are not the primary device, but as a travel cage or a starter they have a place.

Brand-by-brand, with the threads' verdicts

CB-6000 / CB-6000s. The legacy starter. Cheap, easy to find, polycarbonate, a few pre-set ring and tube combinations. Also, by the threads' near-unanimous account, the most-returned cage in the genre. The fixed sizes mean the wearer often guesses and gets it wrong. The shape — a relatively short cage with a flat tip — works for many men and not for others. Threads on r/MaleChastity describe the CB as the cage everyone buys first and almost no one keeps. Skip it unless someone gives you one.

Cherry Keeper. The current sweetheart of beginners and intermediate wearers. Bio-resin, multiple sizes (in 5mm increments for both ring and tube), available in skin tones, light, comfortable, fairly easy to clean. Around €100 shipped. The Cherry Keeper is, in the threads, the most frequent answer to what should I get after my CB-6000 didn't work? Many wearers stay on it for years.

Holy Trainer. Polymer, a bit firmer than Cherry Keeper, a long-running mid-range option (€80–120). The Holy Trainer V4 is the current generation. Comparable comfort to Cherry Keeper; some wearers prefer the firmer feel. It is the second-most-common what's after the CB answer.

Mature Metal. American maker, custom-fit stainless steel, around €350–500 depending on configuration, with a six-to-twelve-week wait. The premium long-term option. The Jail Bird and the Queen's Keep are their two flagship cages. The threads describe them as the cage you arrive at when you have decided this is a permanent practice and you want the device to disappear into the body. Worth the cost only if you've worn a resin cage successfully for at least six months and know your sizing.

Steelwerks Extreme. European, similar to Mature Metal in tier (€500–1500), even more customisable, titanium options, longer wait times. The high end of the market, used mostly by long-term enthusiasts.

The Vice (LockedInLust). Plastic, slightly more secure-feeling than basic polycarbonate, with an anti-pullout pin. A reasonable mid-tier between the cheap plastic cages and the resin tier.

Oxballs Cocklock and similar silicone soft cages. Silicone, forgiving, not really for serious denial but useful as a travel option or a first-night.

The first cage most couples buy is the wrong cage. The second cage is the cage they actually wear. Skip the first if you can; the threads live at Cherry Keeper or Holy Trainer until they live at Mature Metal.

Hygiene, in plain terms

A cage that is going to be worn for hours a day needs a hygiene routine. Daily warm water rinse — in the shower, with the cage on, ten seconds of soap and twenty of rinse — is the baseline. The wearer should be able to feel the water reaching the head of the penis through the ventilation slots; if it isn't, the cage is too closed. Once a week, the cage comes off for a proper wash with soap and a small brush, the genitals get a real cleaning, the ring slot gets attention, and the device is dried before going back on. Skipping the weekly removal is the single most common cause of skin irritation and smell complaints in the threads.

Lubrication for re-application is helpful — a small amount of water-based lube on the inside of the ring as it slides on reduces the daily skin abrasion. Some wearers shave or trim pubic hair to reduce pulling at the ring; many don't. Either works; if there is daily discomfort at the ring, the reasonable first move is to trim the local hair.

Sleeping, in three nights

The first three nights in a cage are the worst. Morning erections — the body's regular nocturnal program — wake the wearer up, sometimes painfully, sometimes just irritatingly. By night four or five, the body learns to dampen the response, and the wearer either sleeps through them or wakes briefly and goes back to sleep. By the second week, the cage at night is ordinary.

First nights, sleep on your back. The classic side-sleeper position can pinch the cage uncomfortably during morning erection; back-sleeping is more forgiving. A pillow between the knees helps. Looser pyjamas or none. The cage can come off for the first night if the wearer is genuinely not sleeping — the practice survives a single night out of cage; it does not survive a week of sleep deprivation.

Travel

Plastic and resin cages routinely pass airport security without comment. Most security agents have seen a small plastic device on the body scanner and flag it for a brief pat-down at most; a calm it's a personal medical device almost always ends the conversation. Many wearers travel with the cage on without issue.

Steel is more variable. Some scanners flag it, some pat-downs are more thorough, and a small minority of incidents involve a wearer being asked to remove it in a private screening room. What the threads recommend: for international flights or any high-stakes travel, switch to a plastic or resin cage for the trip. Bring the steel one in the checked luggage and re-cage on arrival. Titanium is generally lower-friction with airport security than stainless steel.

MRI scans are a hard stop with most steels — including most Mature Metal cages — because of the magnet's interaction with ferrous metal. Wearers who anticipate medical scans should have a plastic backup. Titanium cages and most resin cages are MRI-safe, but always declare any device before a scan.

When to upgrade

The progression we read in the threads is fairly stable. First cage: a basic plastic, used to figure out whether chastity is something the couple wants to keep. If the practice is taking, by the second or third month the wearer outgrows the plastic. Second cage: a Cherry Keeper or Holy Trainer in a custom-measured size, for the first year of serious practice. By the time the wearer has worn the mid-tier cage for six to twelve months and the practice has become structural to the marriage, a custom-fit Mature Metal or Steelwerks is a reasonable investment for the long-term device. Many wearers stop at the resin tier permanently and never feel a need to upgrade; the steel is a luxury, not a necessity. The right cage is the one that fits, that the wearer keeps on, and that becomes invisible enough to the body that the practice can run.