RFID Rewritable Dual Frequency In One ID T5577&IC CUID Black Ceramics Smart Finger Ring Wear for Men or Women

Like the other reviews have said, it's using a gen4 GDM chip for the HF side, and a T5577 for the LF side. It's essentially the ultimate ring, with the two best chips on the market inside of it. Works great for almost every install I've come across, especially if you know how to 'downgrade' credentials. (literally just writing the wiegand in a different format)

So I picked this one for it's dual frequency capabilities. The preprogrammed IC 13.56 Mhz appears to be a Mifare Classic 1k 10 digit. The ID 125khz chip ships blank- this needs to be coded with a reader. The 13.56mhz function works with my digital locks - it works (after coding this into the lock) although the ring needs to be right next to the keypad. I then programmed the 125khz chip with a cheap reader/writer for the time clock. That also works, but it took a bit to get the reader / writer to work. Issue appears similar to the 13.56 chip being very limited range / low signal echo. Otherwise, after getting it going, it does what it's supposed to in a nice format (ie. I don't have to carry keys, fob or cards anymore).

The “dual” does not work properly. You need to rub all over the ring for the sensor to sense the frequency such as 125khz. Waste of time, you’ll look ridiculous having a ring on waving on the sensor many times until it detects. Sometimes it won’t detect at all. These are garbage.

Imaging walking up to your or your clients door that everyone is grabbing a key fob or keycard to gain access while you just give the reader a fist bump. Sizing is near perfect, maybe a shy small, or my measurement. Be sure to get a duplication device and enjoy the convenience. Married to your job? Now you are!

First off, this ring works pretty okay. It has low frequency RFID and high-frequency RFID (NFC) sections, and the NFC section can have its UID rewritten with the Mifare Classic Tools android app, so you can fully clone an existing card rather than having to reprogram the reader to accept this as a new one. The problem is, one side of the ring is one protocol, the other side is the other protocol...and there's not the least distinguishing mark on the ring to show which side is which, or to indicate the optimal angle to present to the card reader for a solid read. Without any modifications, it's entirely up to luck whether you'll have the ring in the proper orientation when you try to use it. I used a small file to scuff up the face of the ring that I found to work for the NFC reader in my apartment, but it's simultaneously an annoying blemish and too subtle to easily notice at arm's length. Just an overall hassle.

Purchased in Nov of 2024, I know some sellers will change the product without referencing that, so be aware. One side is a t5577, not much to say. Out of the box, the ring does come with the HF side behaving like a magic Mifare Gen2 CUID card as the description states), however that isn't strictly speaking true The other side of the ring is a Magic Mifare Gen4 GDM. This means it can be set to enable either Gen2 direct write or Gen1 backdoor command access. As of right now, there are very few door readers that will check for gen4 tags, so if you leave gen1 backdoor commands off, the fact that this ring is a clone cannot be detected by most readers. If you use direct write and accidentally lock the access bits "bricking" the tag and permanently locking it, you can enable gen1 functionality to wipe the card, including the access bits with the backdoor command, and then relock it so it can't be detected as a magic card by readers. the read range out of the box is good, but like every other ring i've had, it seems to be slowly getting worse as the months go by on both HF and LF (although I haven't done a scientific test) There is no stamping on the outside like some rings have, indicating which side is HF and which side is LF The inside is stamped with the US ring size, (mine says #9) and the stamping appears to be on the LF side.

If you had asked me what I thought when I first got it, I wouldve given it 5 stars. The rfid and nfc chips worked exactly as advertised, with the range being limited but that was to be expected. However the nfc chip has stopped working after about a month of use. I'm not entirely sure why only the nfc stopped working, but that's the reason why I've given this 3 stars

Working great wish it had a marking on it to know what side is up