TagsForCells - 20 NFC Tag White Stickers, NDEF Formatted MiFare Classic 1K (13.56MHz) w/ Anti-Metal Layer 30mm Round. For Android and most NFC Readers Pack of 20 Mifare Classic 1K NDEF Pre-Formatted, Anti-Metal NFC Tag White Stickers that are 30mm in Diameter (1.18in or approximately the size of a Quarter) NFC Chip Type: MIFARE(TM) classic compatible w/ NDEF Formatting already done. Better than Samsung Tectiles, as they work on Metal Surfaces. Compatible with Tectile. Ant-Metal Layer lets you stick these on anything and they will work. Memory Size: 1024bytes (1KB), holds vCard, long text Operating Frequency: 13.56 MHz - Data Retention: Approximately 10 years. NFC allows for NO BATTERIES REQUIRED Works with Samsung Galaxy S2, S3, LG Optimus G, HTC One Series and other NFC-Enabled Android Phones. Must be compatible with Mifare Classic Chip. Nexus 4/10 can't write to Tag, but can read UID for some features.