100-Pack 125KHz RFID Key Fobs – T5577 Rewritable Proximity Tags

100-Pack Writable 125KHz RFID Key Fobs – T5577 Rewritable Proximity Tags

Upgrade your access control system with this bulk pack of 100 writable and rewritable 125KHz RFID key fobs. Featuring the versatile T5577 chip, these blank proximity tags can be programmed and reprogrammed to work with a wide range of RFID-based door locks, time attendance systems, and security readers. Perfect for offices, apartment buildings, schools, gyms, and any facility using 125KHz RFID technology.

⚠️ Important Note: These are blank tags — no data is pre-loaded. You must write data onto them using a compatible 125KHz RFID card writer before use. They cannot be added directly to RFID locks out of the box.

Key Features

• Chip: T5577 – Universal, widely compatible rewritable chip
• Frequency: 125 KHz
• Read/Write: Fully writable and rewritable multiple times
• Sensing Distance: 2.5 to 10 cm (approximately 1–4 inches)
• Data Storage Life: Up to 10 years
• Water Resistant: Suitable for everyday carry and light exposure
• Material: Durable ABS plastic
• Color: Blue
• Dimensions: Approx. 27.5 × 35 × 4 mm — compact key fob size
• Quantity: 100 key fobs per pack

What's in the Box?

• 100 × Writable 125KHz RFID T5577 Key Fob Tags (Blue)

Who Is This For?

These RFID key fobs are ideal for:

• Property managers and building access systems
• IT and security professionals setting up multi-user access
• Schools, gyms, and membership-based facilities
• Hobbyists and makers working on electronics or access control projects
• Businesses that need to issue and reissue credentials frequently

Why Choose the T5577 Chip?

The T5577 is one of the most popular and universal 125KHz chips available. It is compatible with many common RFID protocols including EM4100, HID, and others — making it a flexible choice for a variety of access control environments. The ability to rewrite the chip multiple times means you can reassign fobs as personnel change, saving both time and money.

For more information on how RFID technology works in access control and security systems, visit the National Institute of Standards and Technology (NIST) or explore resources at NIH research on RFID-based identification systems.

Looking for related electronics tools and accessories? Check out our 10-in-1 Multi-Head USB Charging Cable or our Tuya WiFi Smart Relay Switch to complement your smart access setup.

Made in Mainland China.

Frequently Asked Questions

Q: Do these 125KHz RFID key fobs come pre-programmed?

A: No — these T5577 RFID key fobs are completely blank. You will need a compatible 125KHz RFID card writer/programmer to write your desired data onto each fob before using them with any RFID lock or access control system.

Q: What RFID readers and systems are these T5577 fobs compatible with?

A: The T5577 chip is highly versatile and can be programmed to emulate several common 125KHz RFID formats, including EM4100/EM4200, HID, and others. They are broadly compatible with most 125KHz proximity card readers and access control systems. Always verify your specific reader's supported protocols before purchasing.

Q: Can these RFID key fobs be reused after being programmed?

A: Yes! One of the main advantages of the T5577 chip is that it is fully rewritable. You can overwrite the stored data many times, making it easy to reassign fobs to new users or repurpose them as needed.

Q: Are these key fobs waterproof?

A: These fobs are water resistant, making them suitable for everyday use including environments with occasional moisture. They are not designed for submersion.

Q: What is the sensing/read distance for these RFID fobs?

A: The typical sensing distance is between 2.5 cm and 10 cm (approximately 1 to 4 inches), depending on the reader being used.