Holy Trainer v4 Nano review

A while back, the folks at Holy Trainer sent me an email offering me the fourth version of their popular male chastity device to wear and, presumably, review. Click on to read my thoughts…

I first put a Holy Trainer on way back in January of 2014. I also reviewed the second iteration, along with the third (in two sizes — Nano and Nub). What’s struck me about each of these devices, including the current one, is how they’ve iterated and perfected the original design. Paying a bit more attention to fit and finish, edges and options. This is a classic almost Apple-esque story of incremental improvement over time.

So, to jump right to the conclusion, version four of the Holy Trainer has done nothing but cement my opinion that there is no better mass-market male chastity device available today. The closest competition is the third version. Other manufacturers have sat on their designs and sold them, practically unaltered, for more than a decade while Holy Trainer have continued to tinker and improve.

I chose to test the Nano size since my review of that one last time found what I thought was a pretty significant flaw. Namely, the underside of the tube exposed too much penis so that the exact part of it that needs to be stimulated to achieve orgasm could easily be accessed. To me, that’s kind of a fatal flaw for a thing that’s supposed to stop exactly that.

Design tweaks

I’m happy to report that the new Nano extends the underside back edge of the tube just enough to make that kind of stimulation much more difficult (if not impossible). I’m told on Twitter they corrected that issue in a later iteration of the v3, but I never wore or even saw that. All I know is the OG v3 Nano had the issue and the v4 does not.

The next best change they’ve made to the HT is a flange around the opening at the end of the tube. This was also present, though with a slightly lower profile, on the v3 Nub and its inclusion on the Nano is welcomed. The purpose of this lip is to protect the extremely sensitive end bits of the penis from excessive and unwanted stimulation. When a penis is compressed into a tube and the tip of it extrudes, it can result in really unpleasant sensation. In the v4, which I wore for nearly two unbroken weeks, I don’t think I felt any of that kind of thing more than once or twice.

The A-ring has also evolved a bit and while I can’t say it makes the device more comfortable (it was already pretty comfy), it does look cooler. In fact, the whole thing has a much more polished finish. Zero sharp edges, everything rounded and swoopy. Again, that helps with comfort, but ultimately it makes the v4 appear more premium than even the v3 which was also noticeably more finished than its predecessor.

All the colors of the rainbow

I was offered a custom color beyond the basic three stock colors of black, clear, and “baby pink.” I went with sparkly dark gray that I’m very happy with. They list more than 30 custom colors but can make something to order if what a client wants isn’t part of that set. The color I got was slightly darker than the sparkly silver they showed on their site and has kind of a Hot Wheels vibe which I dig.


Holy Trainer also offers what they call a “cartridge” which is a small plaque with a short word or small graphic printed on it which is glued into a spot on the top of the A-ring. I already wrote a post about it, but the upshot is at first I thought it as kind of gimmicky but in practice it can be pretty cool.

Bottom line

The Holy Trainer was and remains the best mass-market option for someone considering enforced male chastity, either as a regular part of their sexual identity or just a toy to use situationally in a scene. It’s simple, well-built and designed, and relatively reasonably priced.

If you have any questions not addressed here, please feel free to ask them in the comments.

14 thoughts on “Holy Trainer v4 Nano review

  1. Sounds like a winner. I’ve tried the nub. It’s comfortable but just too small for me. Perhaps the nano is more suitable

  2. Wife periodically locks me in HT (currently at 6 weeks). Started HT V2, now HT V3, went Small, downsized to Nano, now the Nub (grow to nearly 7” but very small flaccid, Nub is amazingly comfy).

    Anyway, reason I’m commenting is that what we’ve both agreed we’d really like is a smaller lock segment, combined with the use of some silicone on the outer-facing part to create a little squishy “give” in this area while making it less prominent. Both would be better for tighter dress pant fronts, hugs w anyone other than her, and kids on laps.

    1. I have wondered similarly if the outer-facing lock part will show under workout lycra.
      I’m going to get a HTv4 nub and see how it goes at first, with that plastic-tab trapping skin back, etc.

  3. Hi, Thank-you so much for your blog. Really interesting and informative – with wonderful honesty.

    I have recently begun a period of chastity at the instructions of my Mistress, and I bought the Holy Trainer v4. Mine had very sharp edges on the connecting part of the ring (where the sheath slots in). I actually cut myself the first time I put it on. I had to file down, and round off, the edges.

    1. Did you get that from Holy Trainer or another site? Doesn’t sound like their work. Hope it wasn’t a knock off. There are so many.

      1. Ah, that might be it. I am in the UK. I bought it from House Of Denial (which, as far as I know, is a respectable seller). It looked legit, and came in a Holy Trainer bag.

      2. It’s really unfortunate that a site like that one that has some stature in the community is trying so hard to sell cheap shit.

  4. I have a 0-ga PA and I currently have a Evotion Bujou cage but I’ve been considering the HolyTrainer v4 Nano. I was wondering if you knew what gauge jewelry might be able to slide through the tip of the opening with the v4 nano or if this might not even be a good idea. On the Holy Trainer site I also see a PA loop of sorts but I’m not sure how that would even work! Do you wear your jewelry inside the tube of the cage and then this wire loop runs through your jewelry?

    If I could just wear my jewelry inside the cage, that would work too but maybe I’d need to go with the small and not the nano. Your thoughts??

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