EM Microelectronic-Marin Compatible Cards & Fobs
EM Microelectronic's read-only 125 kHz chip families (EM4100, EM4102, EM4200) are the baseline of simple proximity access worldwide — the tap behind countless time clocks, gym doors, and parking gates. We supply unbranded, compatible-by-specification EM-family credentials programmed to your system's IDs.
Supported formats
EM Microelectronic-Marin formats we make compatible cards for
Pick your exact format for specifications, OEM part-number references, and a quote. Not sure which you have? Here's how to identify it.
EM4100 (64-bit Read-Only)
The world's baseline 125 kHz credential: EM4100's 64-bit read-only ID, transmitted in Manchester-encoded ASK, is what most simple prox systems, time clocks, and gym doors actually run on.
View compatible cardsEM4102 (64-bit Read-Only Variant)
EM4100's identical twin: EM4102 transmits the same 64-bit read-only protocol, so the two are interchangeable on any EM-protocol reader — a detail worth knowing so you don't overthink a reorder.
View compatible cardsEM4200 (128-bit Enhanced Read-Only)
EM4100 with more room and more reach: EM4200 offers up to 128 bits and better read range while staying backward-compatible with EM4100 readers in 64-bit mode — plus an ISO animal-ID mode for tagging.
View compatible cardsProduct lines for EM Microelectronic-Marin systems: Standard 125 kHz proximity cards
American Key Cards is an independent credential supplier and is not affiliated with, endorsed by, or sponsored by EM Microelectronic-Marin. Our products are unbranded, compatible-by-specification credentials — for brand-original product, order from EM Microelectronic-Marin or an authorized dealer. Brand names appear only to identify the systems discussed; all trademarks remain the property of their respective owners.
Need EM Microelectronic-Marin-compatible cards in volume?
Tell us your EM Microelectronic-Marin format and quantity — we'll quote unbranded compatible cards and fobs, encoded to your facility code, usually within one business day.
Lifetime parts & workmanship guarantee on every card