T5577 EM4305 Copy Rewritable Rewrite Duplicate ID Tag Transponder Can Copy TK4100 EM4100, for 1326 Format HID Card Proximity ID Token Keybobs (12pcs T5577 id Key fobs)

Works as advertised. I was able to clone my RFID card to these key fobs and give them to different members of my family. Would definitely recommend

They worked nicely as expected. Good quality with a nice key ring in each.

they work perfect for copy and rewriting

So far I’ve only wrote my access card onto the yellow fob and it works fine. Hopefully the rest will be good too. It’s a bit larger in size than other fobs I’ve used so a little bulkier. That’s the reason for the 1 star deduction.

I learned the hard way that not all products advertised as T5577 really contain a T5577 chip. Some come with EM4305 chips which are not compatible with HID and other formats.I am happy to say this order is working as expected and does seem to contain a true T5577 chip. All 12 fobs are in great working condition.I was able to write to the following formats: EM4100, H10301, Indala26, IoProxXSF, FDX-A, FDX-B, HIDProx, HIDExt, Pyramid, Viking, Jablotron, Paradox, PAC/Stanley, Gallagher, Keri, AWID

Fantastic keys fobs! Easy to program and works flawlessly. Very happy with these.

These successfully read and write with my Proxmark 3 RDV4! Because of its small size positioning is important. Placing the fob with the dimple side down and near the top center (toward the LED's/FPC connector) of the Proxmark did the trick. Initially they show up as an EM410x tag but doing a `lf t55xx detect` shows them has a T55x7 chip. I was able to wipe the chip and easily reprogram to a HID ATS Wiegand 30-bit. All 12 read/erased/reprogrammed just fine.I tried another similar fob but couldn't get it to write using my Proxmark 3 RDV4, some reported success using the RDV4.01 which has a selectable Q-switch. Mine is older and doesn't have that switch. However, using these tags having that switch was not required.

Received 4 not writeable