Question about Netgear AirCard 790

It needs a micro SIM card (= medium size) that is unlocked for data. This applies to most telephone SIM cards. However, it makes sense to have a corresponding data capacity (i.e. not just 500 MB/month), as the bits & bytes are just rushing with this device.

Any micro-SIM works (an adapter is needed for nano-SIMs), but without data volume in the contract, of course, it makes little sense.