🔍 JT308 RFID Card Reader – Overview

The JT308 is a USB‑connected 125 kHz RFID card reader designed mainly for reading low‑frequency proximity cards such as EM4100‑compatible tags/cards. It is not a reader for MIFARE (13.56 MHz) cards.

📌 Key Features

✔ Frequency: 125 kHz (Low Frequency) — not 13.56 MHz
✔ Interface: USB (Plug‑and‑play — no drivers required on most systems). 
✔ Compatible With: EM4100/EM4200 type cards and similar 125 kHz proximity cards. 
✔ Reads: Card ID/UID, output to computer like keyboard text (e.g., into Excel/Notepad). 
✔ Read Distance: ~3–8 cm depending on card and conditions.
✔ Indicators: LED and buzzer for read confirmation.

📌 Important: JT308 Does Not Read MIFARE Cards

• MIFARE cards operate at 13.56 MHz (High Frequency) — the same HF range used by NFC cards. These require a completely different reader (e.g., ACR122U, PN532, or another 13.56 MHz RFID reader).

• The JT308 only reads 125 kHz cards like EM4100, so it will not detect or read MIFARE Classic / MIFARE 1K / MIFARE 4K / MIFARE DESFire cards.

In RFID systems, a reader’s frequency must match the card’s frequency — 125 kHz readers cannot read 13.56 MHz cards and vice‑versa because they use very different protocols and modulation.

📌 What the JT308 RFID Card Reader Actually Is

✔ Frequency: 125 kHz (Low‑Frequency RFID)
✔ Interface: USB (plug‑and‑play — no drivers needed)
✔ Supports: EM4100, EM4102 and similar 125 kHz proximity cards/tags
✔ Reads: Only the card’s ID number and sends it to the computer like keyboard input
✔ Typical read range: ~5–8 cm depending on the card

This means the JT308 works with 125 kHz proximity cards (e.g., EM4100 type), not with MIFARE Classic, DESFire, Ultralight or any 13.56 MHz cards.