Our Mifare Classic 4K NXP EV1 cards are equipped with a high-quality NXP EV1 chip that has a 4K byte of read/write memory. These cards are designed with a 4-byte NUID that ensures top-notch data privacy and security. They also feature a high coercivity magnetic stripe, which enhances their durability. Key Features:Sold in packs of 100Operates at 13.56 MHZ frequency rangeFully ISO/IEC 14443 Type A 1-3 compliant