This is a combination of RFID 125kHz replicator products, Buyers must use the product correctly, as compatibility cannot be achieved with different frequencies If the replicator is used normally and cannot read or write devices, then it is a compatibility issue, It's not a problem of product damage, please be aware Firstly, the buyer needs the corresponding frequency for reading and writing, which is compatible with low-frequency products such as T5577. This replicator is compatible with all RFID 125kHz smart products, such as EM4100, EM4305, or T5577. Our combination mainly consists of the T5577 combination product package, which is compatible with products such as T5777. If the buyer needs to be compatible with products such as EM4100 or other frequency devices, they will not be compatible. Please purchase carefully before placing an order. Before purchasing, please note that our combination is based on the T5577 chip, and the RFID duplicator is compatible with all low-frequency RFID 125kHz smart products. The combination product is compatible with T5577 low-frequency or hidden cards. If the buyer's product is EM4100, EM4305, or TK4100 with the same frequency but different chips, please confirm the chips before purchasing. Please note.