# RFID key fob, 13.56MHz, S50

- Page: https://sigmanortec.ro/en/rfid-key-fob-1356mhz-s50
- Price: 2.09 RON
- Availability: In stock; 1-2 zile
- Reference: 22115 · EAN: 5940046224969
- Category: Electronic components > Access Control > RFID Cards and Tags
- Package (shipping data): 0.004 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 03:39 (Europe/Bucharest)

## Description

RFID key fob 13.56MHz S50 for access control and identification in projects with Arduino and compatible RFID modules, rewritable up to 200k cycles, with a fixed, non-cloneable ID. It works by induction without a battery, is waterproof and made of durable ABS, attaches easily to keys, and offers fast detection at approximately 3-10 cm depending on the reader.
The RFID S50 key fob is a compact proximity tag that operates at a frequency of 13.56MHz and complies with the ISO 14443A standard, being compatible with a wide range of RFID modules available on this frequency, including RC522, PN532, and HW-126 modules.
It features 1KB of EEPROM memory, organized into 16 sectors with 4 blocks each, each block having 16 bytes, with access conditions definable per block and two security keys per sector, making it suitable for multi-user applications with access hierarchy. It supports anti-collision, allowing simultaneous operation of multiple tags within the field of the same reader module. All blocks are rewritable up to 200,000 times, except block 0 in sector 0, which contains the key fob’s unique identifier and cannot be modified, making the key fob impossible to clone.
Authentication is performed through the mutual three-pass protocol according to ISO/IEC DIS 9798-2, and the key fob supports a 7-byte UID or a 4-byte NUID, with Random ID support for the 7-byte version. Stored data is guaranteed for a retention period of 10 years. Powered passively by electromagnetic induction, it does not require a battery, and the detection distance reaches up to 100mm, depending on the antenna geometry of the reader module.
Made of ABS plastic, it has compact dimensions (40.64 x 31.96 x 3.75mm) and features a loop for attachment to a key ring. It is waterproof and resistant to normal wear and tear.
The key fob is ideal for access control projects built with Arduino, ESP32, STM32, or any other platform compatible with RFID modules at 13.56MHz.
Specifications:
Frequency: 13.56MHz
Standard: ISO 14443A
Model: S50
Material: ABS plastic
Memory: 1KB EEPROM, 16 sectors x 4 blocks x 16 bytes
Power supply: Passive, via electromagnetic induction
Detection distance: Up to 100mm (depends on antenna geometry)
Data transfer: 106 kbit/s
Data integrity: 16-bit CRC, parity, bit coding, bit counting
Authentication: Mutual three pass, ISO/IEC DIS 9798-2
Maximum rewrites: 200,000
Data retention: 10 years
Transaction time: Under 100ms
UID: 7 bytes or 4-byte NUID, fixed, cannot be modified
Random ID support: Yes (7-byte UID version)
Anti-collision: Yes
Security: 2 individual keys per sector
Block 0, Sector 0: Protected, contains the unique UID, cannot be modified
Dimensions: 40.64 x 31.96 x 3.75mm