We can't directly replace the chips in the tags/antennas. The antenna design that is required for ST25TN chips is different than the NTAG21x series chips. Therefore we need to use a different antenna design.
In almost all instances we can supply an identical physical product and just use an alternative antenna. It will physically be the same scan as well and look the same. But the actual internals are likely to be slightly different.
Seritag - 09 Dec 2025
