Lok8u Ltd. and T-Mobile today announced the first U.S. deployment of micro subscriber identity module (SIM) cards, also known as Third Form Factor (3F ...

4FF stands for 4th Form Factor. A SIM card that is simply physically smaller than a traditional (2FF) SIM card or Micro-SIM (3FF) card. See: SIM The electric contacts and circuitry of a Nano-SIM ...

A UK carrier has revealed that Apple is developing an even smaller micro-SIM card, that would allow it to downsize its devices even further.