100pcs 125KHz RFID Key Fob Proximity ID Card Token Tag Keypad Card for Door Entry Access Control System for Security Lock Wholesale, Read Only

Nothing wrong with this product.These particular fobs are used when you are setting up your security system for first time. You can add the fobs number to the security system afterwards manually. You CAN NOT write to these. They are EXACTLY as the description says. If you do not read the description and you can't use these you will be frustrated and write a bad review. Do not miss represent this product in your review. I personally did not read the review and have to send these back. Do not make same mistake as me. I repeat these are for security systems you can manually add these numbered fobs to.Thank for your time.

I've ordered several batches of these fobs from this seller, and the first few batches worked perfectly. However, after distributing them to patrons, we began experiencing access issues. Upon investigation, we discovered that the serial numbers on the fobs did not match what our badge scanner was reading.Further analysis revealed that these fobs do not conform to the standard Weigand 26-bit specification. In a typical 26-bit Weigand credential, the first and last bits are parity bits, and the middle 24 bits contain the card number. This setup allows for a maximum card number of 16,777,215. Some of these fobs, however, have card numbers exceeding this limit, which necessitates that a 25th bit (1st bit isn't being used as a parity bit, but instead a card number bit) be set to 1 instead of 0. This discrepancy is causing conflicts with other credentials, as the access control system is not recognizing these card numbers properly due to the incorrect parity bit settings.

Would not work

Me encanto en servicio y la puntuliad a la hora de la entrega.

Didn't work for me, as I needed writeable units!

I have used several different types of fob, but for some reason these won’t work at all.