Some flex questions

Hey all, it seems like due to an excellent deal posted yesterday, I’m now going to be the proud owner of a gen2 flexM1, and I had a few questions about install that I couldn’t find answers for (this would be my first flex install).

  1. On the listing for it on the DT store, it says “While hemostasis is maintained, do not remove bandaging for 7-10 days”. Has this been the experience of those here? I understand the importance of keeping everything clean, but as a CS student, I need to do a ton of typing, going to class, etc. I’m worried about having to keep the bandage on for that long, and am considering postponing install a few months til we go on break, if needed.

  2. This flexM1 was purchased before the 4G needle was included. My installer has never done a flex install before, but said he was willing to try it, and so the needle method is a must. My question is, I’m considering doing multiple flex installs at once, and I was wondering if the same needle can be used multiple times in succession. I assume it has to be autoclaved between uses, but I’m not sure if they stay sharp enough or whatever. The reason why I ask is that if I have to place a DT order anyway to buy the needle, I was considering just buying another flex implant that includes the needle, and use that one for both. It’s no biggie if I need to add another needle (only $8), but I just wanna know.

  3. Where do y’all have yours? I know the flexM1 is a pretty popular implant, so I’m curious to know where most people have theirs. I’m mainly thinking L4, but I’m a big concerned about the possibility of crosstalk between it and my Spark 2 in L2, due to the much better range of the flexM1. My Spark 2 has pretty awful range as is, so I’m a bit worried about it. If anyone has any experience with similar spacing, I’d love to hear it.

I think that’s everything, thanks in advance for any tips anyone can provide

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I would only consider using a needle maybe twice. It dulls immediately. If you are using it twice in the same session then the professional should be able to avoid cross contamination and just set it on the sterile field after first use and be able to use it again without need for autoclaving… but only if they are comfortable doing that. The needles are of course available separately now with lube (highly recommend lube)…


Agree with this; mine was done without lube and the installer struggled to get full and unhindered penetration sans lube :wink:

That is going to differ from person to person, 7-10 is pretty generous.

My Flex was probably 1 -1.5 days before I removed the Tegaderm, to let it breathe, but I left butterfly bandage / steristrip on another day because I tend to bang my hands up A LOT.
Your body will let you know, but better to leave it on longer than necessary than to remove it early.

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Thankfully my installer 100% recognizes that haha, used plenty of his own needle lube when installing my x-series, definitely made things very smooth.

I’ll definitely get in contact with him for final recommendations then. As I said in my original post, it’s definitely no big deal to pick up an extra needle upon checkout if needed.

That’s a little closer to how long I expected, and leaving the butterfly on for another day or two isn’t a big deal at all, just thought the Tegaderm would be a bit cumbersome to have on for so long (although I’ve never used it before).

I definitely bang my hands on stuff a lot as well, so a good tip there about leaving the bandage on for longer. I’ll also have to make sure to do all of my chores the day before, can’t exactly carry in 10 bags of groceries at once with a healing hand…

Lube does make most things better :wink:

Admittedly it’s been a while since I’ve used any tegaderm, since I have burned the shit out of myself in a while

But it’s honestly a pretty cool setup, think of it like super thin Saran Wrap, that works like a more or less like second skin, it’s transparent super thin and actually sticks pretty good if you aren’t messing with it

I do remember applying it felt overly complicated, like a bandaid with 3x as much packaging and peel strips

I have a trauma of a doctor who once gave me that very same advice after going in for a biopsy.

I had a bad reaction to the ointment he used and, being under the bandaging, it went unnoticed and I gained a nice 1 inch deep scar-hole.

Luckily I grew up a lot, skin stretched and it’s almost unnoticeable now… but I never left a bandage for more than 24 hours after that.

I do understand the reasoning behind it, though:

Technically it would be ideal to not even have bandages. apart from cases where pressure is necessary, constant bandaging is actually a bad thing.

Yet if you keep any wound unbandaged you’ll most likely end up touching it and introducing bacteria and etc…

So keeping it bandaged for as long as you can, as a general rule of thumb, is the lesser evil.

If you’re not 100% sure of your capacity of maintaining strict sanitization and tending to your wound constantly (as in making sure it looks nice, is dry, is anointed, you washed your hands before even looking at the wound, etc…), then do keep it bandaged.

I personally tend to keep those wounds bandaged for the first 3 days, but replacing the bandage about 3-5 times a day (depending on my activities).
If I go out to pick up my takeaway delivery… I will make sure I wash my hands and tend to the bandage! (paranoid, yes. don’t regret)

Then I try to only bandage before going to bed/bath/out, and remove it at any other times.

Heck, I even replaced the steristrips on my flexDF about 3/4 times a day! :sweat_smile:
(do not recommend, though)

Keeping the butterfly strips or steristrips for as long as you can will surely help your healing and scar management.

If you like pain and nasty scars, sure! :stuck_out_tongue_winking_eye:

Seriously, it will lose it’s sharpness after the first time it goes in!

So… you can… but will not do you any favours and even scars get worst from it.

Beyond that, @amal already covered this one.

back of hand on top of the fifth metacarpal, slightly angled towards the void between 4th and 5th knuckles.

Love that spot for something you got to scan about a dozen times per hour…

I also recommend getting/making a splint to hold your hand still for the first couple of days.
It’s a bit overkill, but sure helps prevent accidental “I bent my wrist in a weird way and stretched the incision open” scenarios.

and… good luck!! :grin:

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What’s are your thoughts on liquid skin type products versus or in combination with steri strips

I am yet to find any good steristrip products.
Not sure what the heck my skin does to any tape/tegaderm/butterfly/micropore… but it peels of after a day, tops!

If I add anything slightly moist to any part of it, make it 15 minutes.

So don’t have much experience combining both. :woman_shrugging:

Although I do like the concept of liquid skin stuff. I mean… I do use superglue for bandage quite often! :sweat_smile: can’t be that far! :yum:

I’ll definitely go ahead and get a spare needle then, not a big deal. Thanks for the blunt but honest advice haha, it’s very good to know that it’s a noticeable difference, even just for 2 installs.

Speaking of that, I mentioned in the original post that I was considering having 2 flex implants done at once. The flexDF or the flexDF2 is likely to be the other implant. Either that, or a payment conversion.

While I know this is a super hard question to answer, and super generic, how do you like it? Regarding read range, uses, etc. It seems complex to set up, but I would definitely like some more security in a lot of my applications (mainly PC login), and the flexDF seems like the best option.

If my Uni ID card inquiry goes anywhere, I’ll need one for that purpose anyways.

Also, thanks for the tips on the bandaging :+1: much appreciated

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I was pondering about the same… until I was told that the implant adopts to my lifestyle and not the other way around.

Maybe you can choose a weekend to get the installation done. The inflation decreases in a few days. Than you can put on a finger cot you bought earlier and carry on with your life.

I wouldn’t blame you for taking painkillers to be able to put the right amount of pressure on your implant while it settles.

I generally take my time to get ready for a mod. But once it’s done I’m back to the lab asap.

Do you need a fresh needle for each installation?
This is the $8.- questions I don’t want to find out the answer myself.


It’s a FlexDF2 on the old wedge antenna + blinkie on top.

It is so astonishingly performatic that, comparing to every other chip I have here (not only implants, also fobs and cards) and every other description I hear of… I often think I got an over-performatic chip for some reason! :sweat_smile:

I got it set up for authentication on my Desktop so I just swipe my hand over a reader instead of typing sudo passwords… which I do about a dozen times per hour, at least.
It is insanely comfortable!
Reads really fast (within a quick swipe) and I cant recall last time it failed to read on a single swipe! :star_struck:

I think until Apex comes out FlexDF2 is, imho, the best readily available chip out there! (And I might arguably keep thinking that even post-Apex) :sweat_smile:

And if it does not, that’s what wedgeMN is there for! :wink:

That is very true. Although I still like to give it a few days of rest first, before letting it adjust to me.

I actually dislike adding pressure to flex implants during healing. if the pressure wont be there permanently, it might make the flex settle in a less Ideal placement.

But this varies a lot from person to person.

Very well put! :laughing:

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Glad to hear that you like it, makes it very very tempting indeed… Might need to figure out a different placement for my flexM1, and leave L3 open for a flexDF.

Sadly, AFAIK, the magic NTAG can do Ultralight EV1 emulation, not DESFire EV1 (please prove me wrong though). Even if it can, I don’t think our doors are using DESFire UID authentication. It gets absolutely 0 response from any other 7 byte cards I’ve tried,
albeit not DESFire, and when I attempted to look at the card data, there were 2 applications on the card. I presume one for payment and one for door authentication. Authentication will also sometimes bug out and freeze for a few seconds, which makes me think something deeper is going on. Both our payment readers and door readers are made by the same company, Blackboard. Think it’s all tightly integrated. My only hope for UID authentication is that they have a fixed UID rather than random, but those might have just been for backwards compatibility for the old readers which are fully phased out now (saw a few around the buildings last year, standard readers).

Really want to pick up a magic DESFire card at some point to confirm that theory for certain, but can’t seem to find a place to get them in the US, and KSEC is prohibitively expensive to ship here for a small order. Even if it did work, wouldn’t help me too much without a corresponding implant. Guess if it worked, I could see if amal could do it as a custom conversion, since it should use a fairly standard chip package, I would think. It’s been discussed before, and I think he said it’s too expensive of a chip and too niche of a product to actually sell, but would be open to a conversion.

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Wow! Fancy Uni!!
Finally someone is doing it right! :relieved:

If those are actual Javacard applets, then you need more than a DF2 for that.

If it’s just something like an AES authentication payload, then might be DF2+

Afaik, you can’t use it with the DF encryption based authentication, but depending on how the UID system works you can make it work (only on UID-only DF systems)

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As a well-known STEM college I would hope if anyone did it right it would be them, but from an implant/cloning POV, their competence is infuriating :rage: haha

Sorry for my confusing phrasing there, again my knowledge here is lacking on DESFire stuff, but by applications I meant the seperated application-defined storage onboard the DESFire EV1. There were two application IDs defined on the card, used for different purposes and seperate authentications. I think it’s relatively common for businesses that roll multiple services up into a single DESFire card. Literally no clue about more than that though, cryptography is not yet my strong suit (I do have to take a class on it in the next semester or two which’ll be interesting…). I know the very basics of master key/private keys and public keys when it comes to PGP stuff, but that’s it.

The reason why I stated that was on the DT site along with amals first flexMN post, it states UL_EV1, and it was heavily clarified later on in the thread the difference between Ultralight EV1 and DESFire EV1. I don’t think their UID authentication is compatible, but again, would love to find out I’m wrong here, would make life much easier potentially…

Oh, fair enough! Yes, that’s just the encrypted payload then!

It should not be. although you’d get surprised about how badly so many places implement them. :sweat_smile:

I’ve seen offices with LF fobs where I managed to inject an HF card and make it work! (only on the one door which had a “replacement” dual frequency reader, though)

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Not as bad as a bug in my first NFC safe code I wrote…

It handled 7-byte and 4-byte UIDs seperately, to ensure that the entire UID is checked. However, they’re seperate authentications that are checked apart from each other, and then the value of both authentications is checked. Without going into too much boring detail, I missed 2 lines, resetting the value of the other byte authentication. This had the unfortunate side effect of authenticating with literally any card… :man_facepalming::man_facepalming::man_facepalming:

Used the safe for a solid week without noticing. After all, my implants worked :man_shrugging: got very confused when my student ID opened the safe… and then every test card I had opened it…

Thankfully an easy fix for a low stakes issue (the safe has nothing important in it, mainly use it as a demo item), but I just find it an absolutely hilarious mistake.

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It’s not a terrible bug. just a Bonus feature!!
You added in a fail safe mechanism to avoid people from locking themselves out! :rofl:

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Did you post anywhere on how you achieved this? From some of your earlier posts, it sounds like you’re actually using the secure features of the EV2 which is very impressive, since you’d need an NDA to get documentation on it (or you need to trawl through similar chips application notes).

Which I understand the attractiveness / ease of use of UID based auth, it’s far too easy to clone unless lots of checks are made, and even then it’s usually possible (e.g. DESFire with LAB401 DF emulator)

Not yet, because…

Well… I do have an authentication mechanism for work which links to an RSA tag and a server based auth. Which sux.
So I pulled that thing apart and tossed my code in… :sweat_smile:

So can’t really show since it’s all wrapped up in proprietary stuff which could get me in trouble.

But I do plan on sitting through it and writing a proper mechanism. then I’ll share! :grin:

This damn quarantine situation gave me far more work (the boring platform engineer type of work) to do than I wished for. so I’ve been spending a lot less time on my projects… :pensive:

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(sorry for the bad photo, phone didn’t wanna focus on the bag)

The second-hand flexM1 gen2 from @Ima_Wana_Be has arrived intact! Thanks for the deal + fast shipping!

I was able to write to it using Mifare Classic Tool with 0 issues, successfully cloned several UIDs to it as a test, with ease (and without setting the lock bits :stuck_out_tongue_winking_eye:). The range seems good as well, getting about an inch away from most of my lower power readers.

Now that I have it on-hand, I have a few more questions…

  • I’m not sure how this came at first, but this one definitely doesn’t have any chlorhexidine remaining. I know amal has said in the past that it evaporates over time, especially with the old process (no clue how old this particular flexM1 is): “I’ve had to revise the “squish pack” sealing process… the older pack sealing method left an “escape route” for alcohol vapor (but not liquid), and that has since been solved.” I’m assuming all it needs is a soak in a bit of chlorhexidine before being implanted, but some more details on how to go about that would be appreciated (how long to leave it, how long to let it evaporate, if my piercer should have access to chlorhexidine vs. if I need to buy it myself and bring it, if needed where to buy it to be bio-safe, etc). Any help here would be appreciated, don’t want to mess things up. I searched, but couldn’t find many small details on the process of cleaning a dry flex (besides people just saying to throw it in some chlorhexidine).

  • I tried to capture it in that photo the best I could, but is it normal for the chip to appear not quite square from the back side? This is a minor thing, but mine is kind of a parallelogram shape. Not sure how the process works there, but just wanna check. It was kinda freaking me out at first.

Thanks again!