MF classic 1K key tags Specification:
- Chip: M1, S50
- Function: Read/Write protect by password
- Memory: 1K Byte
- Size: Diameter 25mm
- Material: PET +M1 1K chip + Release Paper
- Frequency: 13.56MHz
- RF Protocol: ISO 14443A
- Can work with RC522 and PN532 Readers

IMPORTANT:
NOT work if stick on metal surfaces.

Features and Benefits
Contactless transfer of data and power
Operating frequency is 13.56MHz
16-bit CRC data integrity check, parity check, bit encoding, bit count
Support random ID (7-byte UID version)
7 bytes UID, 4 bytes UNID
Anti-collision
Working distance up to 10cm depending on antenna geometry and reader configuration
Data transfer efficiency is 106Kbps
Typical ticket transaction time is less than 100ms(including backup management)

When writing data by a 13.56MHz writer/ reader, please note the following:
1. Basic Communication Check: A reader operating at 13.56MHz is required for data read/write operations. Verify that the reader can successfully detect the M1 tags and retrieve the M1 tag's UID.
2. Key and Permission Verification: Authenticate the target sector of the MF Classic 1K RFID tag using a known valid key (if possible, start with the default key FFFFFFFFFFFF).
Sector Access Bits: This is a common cause of write failures. Each sector's tail (Block 3) in M1 Classic 1K tags contain access control bits that define read/write permissions for Key A and Key B on each data block. If an access bit is set to disallow writing (e.g., marking a data block as read-only) or an invalid combination is configured (e.g., all zeros), the entire sector may become permanently locked, preventing any further write operations.
Sector Write Protection: Note that Block 0 of Sector 0 (storing UID and manufacturer information) is permanently write-protected on standard M1 tags and cannot be written to.
Quantity: 20 pieces round 13.56MHz RFID tags. Diameter: 25 mm / 1 inch. This MF classic 1K tag is adhesive, can be pasted. Please check our store and there are many small quantities for you to choose from, you can buy the experience with a small quantity first. 【Note 1: The UID cannot be changed or rewrited】【Note 2: Please make sure this M1 S50 RFID tag is compatible with your system before purchasing】
Chip: High quality M1 Classic 1K chip, working frequency: 13.56MHz, 1K byte memory, ISO14443A protocol, password read and write protection, high scan strength, easy to program. Service life: 10 years, 100,000 writes. UID Can’t be changed and rewrite. Non-NDEF format. 【Note: This MF 1K tags is MF1 S50, donot compatible with MF0, MF2 and MF3】
Application: These MF1 S50 RFID stickers proximity cards work with KABA, SAFLOK, MIWA and ONITY LOCKS, also compatible with RC522 and PN532 readers. But they can NOT work with HID, Salto and Assa Abloy Locks/Systems, TagMo, etc. 【Note: If you want to add the M1 RFID tags to your lock system, please ensure that your system is the same frequency 13.56MHz】
Compatibility: Compatible with RC522 and PN532 readers, all M1 Classic 1K stickers commercial access proximity cards are pre-programmed with a unique ID, 4-byte UID. UID cannot be changed, factory default key: FF FF FF FF FF FF, compatible with most access control systems.【Note: Not supported to use on metal surface and strong magnetic field】
Hassle Free Warranty: We are confident that you'll love our NFC Tags. If, for any reason, you're not satisfied with the 13.56 mhz rfid tags stickers, please do not hesitate to send the seller a message through Amazon and we will respond within 24 hours.