10pcs Blue 13.56MHz UID Changeable Keyfobs Token NFC Tag Rewritable RFID Writable Access Control Key Card Used to Copy/Clone Card blue

works perfectly with Aqara U200. An idea is use it for contractors and once the job is done, delete the user from the Aqara app so security is not compromised.

Used this for simpled smart lock and works as expected. Great value for price .

Not UID writeable.

These fobs are as described. Block zero (0) is 100% rewriteable, that does include the UID. I was trying to rewrite these with some software I wrote myself wondering why it wasn't working at first but I also learned that these Chinese-made fobs need a certain "unofficial" sequence of bytes sent to it in order to unlock block zero which are in fact used in certain libraries. Once I figured that needed to be done I was able to write whatever data to it I wanted. Unfortunately I had to knock off a star since the build quality wasn't great. The clam shell design of the case came apart quite easily and the little disc inside containing the chip could fall out. I think they just click together with not much holding strength so I pre-emptively took them apart and actually glued the insides together before deploying them. Other than that, they work as expected.

All data editable

UID is changable multiple times. Whole tag is rewritable (as long as you do not lock it) These are Chinese Magic Gen1 Perfect for making a 100% clone of an existing tag.

These tags appear to need special commands sent, not a standard Mifare block 0 write and so none of the (many) NFC apps I tried on a Pixel 3 XL were able to write to block 0.

Works brilliantly for a great price

Fonctionnent tous sans souci, pas eu un seul problème.

no fueron compatibles con otros llaveros identicos. supongo que es por la frecuencia que manejan.

Yep, I could actually modify the UID (block zero) and clone a key that I had lost.

Cuando me hice con un Flipper Zero, amigos que en su urbanización usan llaveros NFCs para entrar me preguntaron si podía hacerles nuevos, puesto que, en algunos casos, te pueden cobrar bastante (hasta 20€ me han dicho). También debo decir que existen aplicaciones para móviles que te permiten clonar, por lo que no necesitas un Flipper Zero. Tras un primer intento infructuoso al comprar llaveros cuyo UID no era reescribible (ignorante de mi), me hice con estos que específicamente lo son. El UID es un identificador único del llavero por lo que para que puedas usar uno clonado en sistemas donde están registrados solo unos UIDs específicos (es decir, que solo funcionan con los llaveros que ellos quieren), estos llaveros clonados tienen que permitir cambiar su UID por el del llavero original, para que hacerse pasar por ellos. El caso es que con estos no he tenido problema para clonar varios llaveros de varias urbanizaciones y teniendo en cuenta de que estos llaveros salen a medio euro cada uno, creo que es rentable. Lo único, y esto es para quienes usen el Flipper Zero, es que a la hora de identificar el llavero con el Magic, a veces no lo hace bien a la primera, y hay que asegurarse que lo identifica bien antes de intentar grabar en el.

worked perfectly, was able to store the data i needed, no issues, works with my android phone. no defects, checked everyone of them, and they all worked perfectly. great for adding to a geocache, or storing some temp data.