Original Classic 1K EV1 Cards Our Best-Selling Access Control Card Operates at 13.56 MHz with a 4-Byte Unique Identifier (NUID) Buy with Confidence. The Classic® 1K EV1 Access Control Card, our best-seller to date, operates at 13.56 MHz and features a 4-byte Unique Identifier (UID) and 1KB of memory. These blank white cards can be easily personalized with any retransfer ID card printer, allowing you to add your company logo and branding to the card surface with ease. As part of the Classic family, these cards are manufactured to comply with the ISO/IEC 14443 Type A standard and are primarily used for public transport ticketing and access control. Frequently Asked Questions Q: What is a MIFARE 1K card? A MIFARE 1K card is a high-frequency card operating at 13.56 MHz, with 1KB of memory. This memory is divided into 16 sectors, each sector containing 4 blocks, and each block containing 16 bytes. This card is ideal for access control systems, public transport ticketing systems, time and attendance systems, and more. Q: What is the difference between MIFARE 1K and 4K? A: MIFARE Classic 1K has a smaller memory capacity than MIFARE 4K. The 1K capacity MIFARE Classic has 16 sectors of 4 blocks, whereas the 4K capacity MIFARE Classic has 40 sectors, 32 of which are the same size as the 1K sectors and 8 others are four times larger.