@kaia @vel
They have high-precision timers in them and a battery that lasts for a few years. Long time ago I was working for a company that had been using similiar thingies, SecurID tokens for OTP: https://breloma.m0xee.net/notice/AaAgSknbfuZfPeMin2
They are sold together with software that integrates well into other products, every box of 50 or so tokens came with a CD that had their cryptographic keys that you had to import into that software.