13.56MHz Rewritable UID RFID IC Card Keyfob – 1KB Chip

Meet the 13.56MHz UID Rewritable RFID IC Card & Keyfob — a compact, versatile proximity card solution ideal for access control systems, smart door locks, time-attendance readers, and hobbyist RFID projects. With a changeable UID chip, you can rewrite and clone compatible card data quickly and easily using a standard RFID card writer.

Key Features

• Working Frequency: 13.56 MHz — compatible with most standard MIFARE readers
• Memory Capacity: 1KB storage for flexible data management
• Rewritable & UID-Changeable: The chip UID can be rewritten multiple times, making it perfect for testing, development, and cloning applications
• Compact Keyfob Form Factor: Small, lightweight, and easy to carry on a keyring — slim enough for a pocket or bag
• Durable ABS Shell: Rugged ABS construction withstands daily handling and light moisture exposure
• Self-Adhesive Coil Option: Includes a coil design suitable for self-adhesive mounting applications
• Passive Power Supply: No battery required — powered inductively by the RFID reader
• Broad Compatibility: Works with standard 13.56 MHz MIFARE Classic 1K readers and writers

Specifications

• Frequency: 13.56 MHz
• Chip Type: MIFARE Classic 1K (UID changeable)
• Memory: 1KB
• Material: ABS
• Power Supply: Passive (reader-powered)
• Diameter: 21.6 mm
• Form Factor: Keyfob / Self-Adhesive Coil

Who Is This For?

This rewritable RFID keyfob is a great pick for electronics enthusiasts, smart home tinkerers, security system installers, and developers who need a flexible, reprogrammable card for prototyping or everyday access use. Whether you're setting up a DIY door lock, testing an RFID reader, or managing a small access control system, this keyfob delivers reliable performance in a pocket-sized package.

For more background on RFID technology and its applications in security and identification, visit the NIST Guidelines on Securing RFID Systems.

Frequently Asked Questions

Q: What is a UID-changeable RFID keyfob and how does it work?

A: A UID-changeable RFID keyfob operates at 13.56 MHz and contains a rewritable chip whose unique identifier (UID) can be overwritten using a compatible RFID card writer. This makes it ideal for cloning, testing, and development with MIFARE Classic 1K systems — no battery is required, as it draws power passively from the reader's electromagnetic field.

Q: Is this keyfob compatible with standard RFID door locks and access systems?

A: Yes. This 13.56 MHz RFID keyfob is compatible with most MIFARE Classic 1K readers and writers, which are widely used in door access control systems, time-attendance machines, smart lockers, and hobbyist electronics projects. Always verify your reader's chip compatibility before purchasing.

Q: Can the UID be rewritten multiple times?

A: Yes — the chip is designed to support multiple rewrite cycles, making it a durable and flexible option for testing environments or applications where the card ID needs to be updated or cloned repeatedly.