Crystal card is a personalized RFID smart card featuring a clear design with a three-dimensional appearance, offering dustproof, waterproof, and vibration-resistant properties. Application: Suitable for patrol systems, attendance systems, access control systems, one-card systems, and other RFID identification fields. Size: 31.5 x 28mm Chip: NTAG213 Storage Capacity: 148 bytes Operating Frequency: 12.0014.50 MHz Write Endurance: 10,000 cycles Data Retention: Up to 5 years Read/Write Distance: 110 cm Supports Protocol: ISO14443 Product appearance and printed text may vary by batch; this does not affect functionality. Color: Black Material: Epoxy resin Package Includes: 20 x NFC Smart Cards Note: The package includes only the items listed. Other accessories are not included. Note: Lighting effects and monitor settings may cause slight color variations between the image and the actual product. Measurement tolerance: 13 cm.