This EM-4100 family product is designed to work with our RFID Card Reader and RFID Reader USB and are considered passive tags. Each tag has a unique 10 digit ID, so multiple tags can be used in a single project and may be purchased from Parallax in any quantity.

Features:
EM4100 Family Passive Tags
125 kHz activating frequency
Readable from 2 to 5 inches of RFID reader
Thin Package

Compatible with These Kits:
RFID Card Reader (Serial)
RFID Card Reader (USB)
RFID Read/Write Module (Serial)