(*****) Uhlmann & Zacher CX2172 NFC / BLE smart door handle review

At long last, I have received the first of - at least - two Uhlmann & Zacher CX2172 smart door handles, and installed it on my office door at work.

And it’s a winner… with Flex-series implants. No joy with glass implants, as I already knew.

Check it out:

This is a great product for those who can’t modify their door, such as tenants or students in dorms.

I am in that situation at work: all our locks are master-keyed, any coworker must be able to open anybody else’s office door with their key, and the security company also.

So I had to retain the original lock. Also, there was no way my company would let me replace the lock case, because it’s obsolete and I’d have had to modify the mortise in the door. My boss is very nice and understanding, but I don’t think it would extend that far :slight_smile:

The CX2172 is just a handle: provided you have the proper rosette for your style of lock and a couple of suitably long M5 screws, all you have to do is unscrew your existing handle set, replace the square spindle, and install the CX2172 in lieu of one of the original handle. 5 minutes to install, 2 minutes to enroll your implant, and you’re in business.

The NFC authentication is done on UID alone. That means it works with any kind of ISO14443A implant, which is good news. As you can see in the video, I’ve tested it with my doNExT (zero issues, humongous range as you might expect) and with my flexM1 (a bit more finicky, but very easy to hit the sweet spot nonetheless). My IAR magic M1k doesn’t even wake it up, but no surprise there.

The CX2172 can also be unlocked with a cellphone over Bluetooth. The distributor that sold it to me (Bitwards out of Helsinki, Finland) has a remote administration tool that lets you give someone temporary access, based on time or identity. I’m not personally interested in that, but my company is. I haven’t had time to test-drive that yet, but I will soon.

Quality-wise, it is VERY well made: very solid, quite heavy, no slop anywhere in the mechanism, nice brushed metal finish. Quite obviously German-made: that ain’t no cheap Chinese product, nosiree.

This is what you get in the box:

  • The handle itself (left or right - must be specified when ordering)
  • The replacement square spindle
  • A small hex wrench to install the CR123 battery (mine came with the battery installed)
  • A service key card to enroll and delete access cards - well, implants in my case
  • A system card, the purpose of which is a mystery to me but I intend to find out
  • A teeny tiny folded manual printed for smurfs that give no useful instructions whatsoever

And if you’re curious, here’s the reverse side of the rosette:

I’m not gonna post pictures of the business side of it. There are plenty of photos of that on the internet. Your search engine of choice is your friend.

Finally, the painful bit of information: I paid 348 euros ex-VAT (451.65 EUR with VAT and shipping costs included). That included the two programming cards sold for 25 euros which, strictly-speaking, I didn’t need. But I bought them anyway because… well, I’m clumsy and I figured I might well manage to brick the thing from the get-go if I presented my own card for enrollment as a programming card.

My conclusion: highly recommended if you have the money and a Flex-series implant - or you need an excuse to implant one :slight_smile:

[EDIT: if you’re in Scandinavia and you’d like to get your hands on a U&Z CX2172 door handle, you can contact Bitwards: they’ll be happy to supply it to you.]


looks awesome, love how compact it all is.

Sad about the glass implants but you win some you lose some.

You know it’s a Rosco official video when you see no shoes

Thanks Rosco, I have updated the Google sheets and linked to your awesome post

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Hehe… I didn’t even notice. I see them all the time you see.

Dammit I was going to make the no shoes joke, got distracted

Honestly you guys, I just don’t get it: you see my hands in the entire video, but two video frames worth of half a blurry foot get you to react?:slight_smile: It’s gotta be a psychological thing.

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That’s a quality looking bit of kit. I’m guessing this isn’t weatherproof in anyway and just intended for internal doors?

This is a feature I’ve previously considered for perhaps a cleaner or trustworthy tradespersons etc.

Being lazy I did consider a cleaner a few years ago. One of my sisters introduced me to this Ukrainian woman who cleaned, she told me I pay for the cleaning but the sex would be free :wink: :smile:

It’s IP66, so it should be okay for outside installation also.
Additionally, there’s a rubber O-ring on the rosette. Surely they didn’t put that there for nothing.

I wouldn’t trust it here in Northern Finland by -30 degrees though…

Haha! That was amusing :slight_smile:

Oh right okay. Would nicely suit the side door into my garage…I’ll consider the $$$

Yeah that’s why I do most things myself.

I think it’s well worth the expense. But yeah, it’s not cheap. Having said that, quality rarely is.

But crucially, if you look for a commercial option to solve the problem this handle solves - which is adding RFID access to a dumb door you’re not allowed to modify or re-key without mounting an eyesore of a homebrew arduino + servomotor affair on the other side - that’s pretty much your only option.

For the sake of completeness in this review, I should mention that the CX2172’s reader is in fact plenty powerful enough to read glass implants.

The issue, as with many other battery-powered NFC devices, is that it doesn’t wake up: the probe pulses it sends out to detect something in the vicinity aren’t perturbed enough by the presence of a glass implant.

As always with readers that don’t wake up, there’s a surefire way to get them going, and that’s to present your glass implant and a proper inductive load at the same time. Here for instance, with a DT field detector card, my glass IAR works just fine:

The problem of course is that it completely defeats the purpose of using an implant.

One firmware improvement that would make it work with any glass implant is if it tried to read at full power for 2 or 3 seconds when the handle is depressed. That way one could wake it up manually just by working the handle.

But if some prankster did that repeatedly, that would quickly deplete the battery. I guess it’s not worth the trouble just for a few implantees. But maybe I’ll suggest it to the manufacturer.


im sad because you even point out dorms as an example where you cant mess with the lock but im in dorms now and can tell you, this still wont work.

  1. the lock and handle are one unit
  2. the housing guys allow absolutely nothing to be done with the locks. i would be fined $1000 and possibly removed from dorms if i tampered with the dorm lock in any way.
  3. And for some reason, adding my own arduino/ servo project on the inside is also something they would consider ‘tampering’ (even though i would set it up so their master key still overrides my servo, and it modifies nothing about the existing lock, just interacts with it.) it pisses me off and im sad.
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Well at some point some modification is required. This handle allows minimal and totally reversible modifications, as would an Arduino and a motor. I know when I was a student, the guy in charge would have been okay with it - hell, he was okay for me to install a ham radio antenna on the roof.

But if the powers that be at your uni / fraternity are anal won’t allow anything at all, then there’s not much you can do either way. All you can hope for if you go for a homebrew solution on the MTFT side of the door is that nobody notices or rats on you. That ain’t much of a solution…

Out of curiosity, have you tried to approach them? I mean, if you’re stuck with the rules, there’s not much to lose in asking upfront.

unfortunately i have.

i had my ra (the upperclassmen student designated as a kind of ‘supervisor’ of the floor) ask residence life since he had contacts, they said ‘idk, what does the contract say?’

i responded with the exact wording which was no tampering or modifying. they then just said no. which confuses me because under the definition of those words i should be fine.

Housing’s word overrides res life so i could email the housing guys but i havent gotten to that yet and im not hopefull…

the worst part is that everything else on campus is mag stripe so i cant even use my implant elsewhere and since i asked them already i cant take the approach of just doing it and hoping noone finds because when they do find it in a fire inspection or something, i have no excuse because i was already told no… :frowning:

It’s sometimes better to ask for forgiveness than permission. :innocent:

the point of that comment was actually to say that its not. if i never asked then i could use the excuse of ignorance but now with no excuse they’ll probably go and hit me with the $1000 fine without even hearing me out because they now can say that i consciously and deliberately broke the rule

then again, if I do it after fire inspections are done and they never find it…

I don’t know where you study, but would there be other, less strict, suitable affordable housing options for you around your uni?

i mean i could live at home and commute if i wanted but i wanted to be on campus for a variety of reasons. its not that bad.

Would you be allowed to build an arduino gadget?

Not really tampering or modifying if it doesn’t alter the original

I guess not: