# Cartão Crachá Magnético Aproximação RFID 125kHz: A Complete Guide ## What is a Cartão Crachá Magnético Aproximação RFID 125kHz? A **Cartão Crachá Magnético Aproximação RFID 125kHz** is a contactless identification card widely used for access control, time attendance, and security systems. Operating at a low frequency of 125 kHz, these cards enable quick and convenient proximity reading without physical insertion into a reader. From my personal experience working in corporate security, I've seen how these cards streamline entry processes in office buildings—simply holding the card near the reader grants access within seconds. This efficiency not only improves workflow but also enhances security by reducing tailgating incidents. ## Technical Specifications and Parameters When evaluating a **Cartão Crachá Magnético Aproximação RFID 125kHz**, it's crucial to understand its technical details. Here are the key specifications: * **Operating Frequency:** 125 kHz ± 5 kHz * **Chip Type:** Common chips include EM4100, EM4102, TK4100, or compatible. * **Chip Code Format:** Typically 64-bit or 128-bit Read-Only (ROM) with a unique factory-programmed ID. * **Communication Protocol:** FDX (Full Duplex) or HDX (Half Duplex). * **Read Range:** Typically 5 cm to 10 cm, depending on the reader's power. * **Card Dimensions:** Standard ID-1 format (ISO/IEC 7810): 85.6 mm × 54.0 mm × 0.76 mm. Thickness can vary (0.8mm to 1.2mm) for magnetic stripe composite cards. * **Material:** PVC, PET, or composite materials. Magnetic stripe variants include a high-coercivity (HiCo) stripe (2750-4000 Oe) for data encoding. * **Data Capacity:** Chip stores only a unique identifier (UID). All associated data (user name, access levels) is stored in the system database. * **Memory Type:** Read-Only for most 125kHz cards. * **Standards:** Complies with ISO 11784/11785 (FDX-B) for animal identification, often adapted for access control. > **Important Note:** The above technical parameters are for reference and illustrative purposes. Exact specifications, including chip code details and custom dimensions, can vary by manufacturer and order. For precise data and product-specific details, please contact our backend administration team. ## My Perspective on Security and Convenience In my opinion, the **Cartão Crachá Magnético Aproximação RFID 125kHz** represents a perfect balance of convenience and basic security for many applications. While not as secure as higher-frequency