Note: They are blank RFID tags, no data inside. You need to write data into them to use.
Frequency: 125kHz; Sensing Distance: 2.5 to 10 cm (1 to 4 inch); Data Storage Life: 10 Years.
Writable & Rewritable. It can be erased and written 100,000 times. Suitable for making new and back-up tags, with the 125kHz RFID card writer/copier.
Chip: ATMEL T5577 (compatible with other universal 125kHz tags).
Approx Size: 1.4*1.1*0.2 inch. High-Quality Copper Coil inside. Casing Material: ABS Plastic. Waterproof & Durable.

1. Material:ABS
2. Frequency: 125KHz
3. chip: Original ATMEL T5577 (The best rewritable chip)
4. Package included: 10pcs black T5577 RFID keyfobs
5. Working Mode: Read-write modes - Can be used in 125KHz RFID card Copier/ Duplicator
6. Storage Capacity: 330 bit (264 free bit availability)
7. Reading distance is 0 - 10cm

Package include:
50PCS* T5577 RFID rewritable 125khz writable Keyfobs

Please note it need to write the ID on it before you read, it's original chip. Can write in normal id format and HID format WG26, If it can't work with your system, please contact with us first. we will give you a satisfying answer.