YARONGTECH 125khz rewritable T5577 Sticker Black Coin Adhesive Back Dia 25mm Thickness 1mm -5pcs

Those work great and finally I’m never locked out since I can simply stick these to my phone, which I never forget :)

Works great. Programmed with the flipper

So easy to use with those $10 reader/writers. I use these instead of carrying around badges, building passes, gym pass, etc. They all just discretely stick to the back of my phone. Adhesive is quite strong.

amazingly thin, works perfectly. I stuck it to my Otterbox phone case, and it's less bump than the camera lens. color even blends in with the black case. it's nearly invisible.

Happy to say that these are compatible with HID systems. Recently moved into an apartment where you have to use a fob just to get into the leasing office and pool so it's become super annoying to have to have my keys with me all the time. I was able to get an RIFD duplicator and copy my original fob onto the se tags and I put one of them on the inside of my Apple Watch band and it has done me well. Gone are the days of not having my stupid fob to go get a coffee from the office. I just simply tap my watch band to the reader and boom. It works. Definitely worth the money for sure. Seems to be sticking to my watch band pretty well so far, time will tell.

Works as intended and are very sturdy. Adhesive is quite strong as well.

Gods gift to man. Buy this! If your building has key fob access get this. Game changer

I love this product. It's easy to write the code. And it sticks perfectly to the back of my phone. No more key fobs 🙌

Don't complain, its functionality unless you have written any data to the chip. Once data are (maybe read and copied from another to this chip), then it is great little, good looking product to replace any like credit card badges or key fobs. Note: I used my Flipper Zero to copy my 125kHz badge card and wrote same data to the chip and voila... All OK. But, if have only reader and used to upload a fixed hash to database, then re-consider purchase. You simply need RFID writer

Have used for door entry ,so now do not need to carry my key fob have stuck it to my phone case. You need a rfid reader and writer to use this product.

This YARONGTECH T5577 sticker is a basic 125kHz rewritable RFID tag designed for compatible access systems and readers. It’s thin, lightweight, and easy to attach to flat surfaces, making it convenient for everyday use. The adhesive backing holds well, and the tag itself feels flexible but durable enough for regular handling. Since it’s a T5577 chip, it’s rewritable and meant to be programmed with a compatible system before use. Overall, it’s a straightforward, no-frills RFID sticker that does exactly what it’s supposed to do—nothing fancy, just reliable performance when set up correctly.

Son perfectas.... He podido copiar las 5 y funcionan perfectamente. Totalmente recomendables. Lo puedes dejar entre la parte trasera del móvil y la funda y así evitas otra llave.

Excellent product. The RFID reader/writer I bought came with fobs and cards but none of them worked. I purchased these and they have been a life saver. Highly recommended.