The TDSi 2920-3003 is a Mifare 4k card that has serial numbers printed onto them that are high-quality access control cards. They’re ideal for a wide range of uses that operate at a 13.56 MHz frequency. These cards also have a 4K-byte memory and come complete with a unique serial number that makes issuance easy.Product weight: 0.00 kg- Sold in packs of 100- CR80 card size (86mm x 54mm)- 13.56 MHz operating frequency