1. The card is fully compatible with IC 1K cards. 2. Block 0 of the card (the block containing the UID) is rewritable and can be modified multiple times. 3. Block 0 can be modified directly using a standard IC card reader/writer—no special equipment required. 4. Default password: FFFFFFFFFFFF Specifications: Storage capacity: 8 Kbit, 16 sectors, two sets of passwords per sector Operating frequency: 13.56 MHz Communication speed: 106 kbps Reading distance: 2.5–10 cm Read/write time: 1–2 ms Operating temperature: –20°C to +85°C Endurance: >100,000 write/erase cycles Data retention: >10 years Compliance: ISO/IEC 14443, ISO/IEC 10536 Applications: Prepaid water meters, campus cards, transit stored-value cards, highway toll systems, parking management, community access control Color: Assorted Material: ABS Package includes: 50 × UID programmable cards Note: Color may vary slightly due to screen settings and lighting conditions. Dimensional tolerance: ±1–3 cm.