A:Answer It utilizes a micro (sized) SIM, or you could likely use a smaller nano (sized) SIM in a micro adapter.
Figure out if you need a GSM or CDMA SIM card based on the corresponding major carrier you intend to use (AT&T, T-Mobile, Sprint, Verizon, others), as well as virtually all of their related MVNO's (Mobile Virtual Network Operators--TracFone, StraightTalk, Cricket, MetroPCS, etc). The EXCEPTION is Boost & Virgin Mobile and likely any other MVNO that utilizes the Sprint network; it appears Sprint restricts their MVNO's to only Sprint or affiliated MVNO-branded handsets, and thus this unlocked Motorola will NOT work.
It's important to get the SIM card from the proper company. For example, if you want to use a TracFone (an MVNO) plan on either the Verizon (CDMA) or AT&T (GSM) network service, you need to get the appropriate CDMA or GSM SIM card from TracFone, NOT from Verizon or AT&T.