S203 RFID tag – programmable proximity key fob

The S203 RFID tag is a programmable proximity key fob.
This popular key fob offers versatile applications. It features user-accessible, non-volatile memory, allowing for the copying (cloning) of serial numbers from standard 125kHz "Unique" tags. Once programmed, it works with most intercom readers and access control readers compliant with the 125kHz "Unique" standard. It is compatible with the "legendary" EM 4100 chip. This standard, though outdated by today's standards, is still widely used. This key fob is used for identifying individuals in systems with the lowest security levels.

S203 RFID tag – programmable proximity key fob, including some useful additional information:

The S203 can be attached to personal keys. This key fob works seamlessly with most readers designed for the "Unique" 125kHz standard. Due to its high durability, it can be used both indoors and outdoors. Its compact and aesthetic casing, allowing for easy printing, and its high reliability have made this type of key fob popular on the Polish market for many years. The reading distance is generally not long, but it allows for convenient use. Example applications include proximity door and gate opening via intercoms and readers, hanging identification tags for objects and animals, etc.

S203 RFID tag keychain in brief:

High environmental and mechanical resistance
Satisfactory range and ease of reading
Simple connection to a keychain
Passive tag - no batteries required
Possibility to program any serial number compatible with "Unique" 125kHz
Small dimensions and aesthetic housing
Popular on the market
Without printed number

Additionally, the tag has the following technical parameters:

Housing material: ABS
Dimensions: 40x32x4mm
Weight: 4g
Commercial unit packaging: 100pcs
Operating frequency: 125kHz
Integrated circuit used: 5577
Serial number: to be programmed
User-accessible memory: 363 bits
Serial number printing standard: none