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How the compatible Keri Systems MS / NXT (K-Format) works
The Keri Systems MS / NXT (K-Format) is a 125 kHz low-frequency proximity credential — the band most legacy prox readers use. Its data structure is Keri proprietary K-format / MS (Megastar) PSK - distinct facility-code ranges + internal mapping; NXT borrows Pyramid data structure ('N' prefix = NXT); FSK2 RF/50 inverted. When you present a credential, the reader decodes that exact structure and passes it to your access-control panel as a card number it recognises.
We build the compatible Keri Systems MS / NXT (K-Format) by encoding the matching data structure onto a programmable T5577 / EM4305 chip. Once written, the credential presents the same bits, the same facility code, and the same card number your reader already accepts. That is what "compatible by specification" means: not a generic look-alike, but a credential engineered for the exact format your system expects.
To order, tell us the part number or format printed on your existing Keri Systems card, and our specialists confirm the encoding before anything ships. Bulk and reorder quantities are welcome — pricing is a fraction of OEM list, and every credential is verified to read on your existing equipment.
Also known as
Keri · Keri NXT · Keri MS · K-Format · ker 125khz · KC-10X · MT-10X · PKT-10X
Keri Systems and all other brand and product names are trademarks of their respective owners. Security ID Systems is an independent manufacturer and supplier of compatible access-control credentials and is not affiliated with, authorized by, sponsored by, or endorsed by these companies. Brand and format names are used only to identify the systems our products are compatible with.