TagsForDroid 2 NFC Tags + 1 NFC Key Chain (MIFARE 1K) We recommend you get our NTAG203 products! They are newer and more compatible technology! 2 NFC Tags + 1 FREE NFC keychain NFC Chip Type: MIFARE(TM) classic compatible - Memory Size: 1024bytes (1KB) Operating Frequency: 13.56 MHz - Data Retention: 10 years will NOT work on Galaxy S4, NEXUS 4, or 10.. Purchase our NTAG203 NFC tags instead if you own these devices.