Here is a card for use in Cuba
 

Just visited Cuba for a few days. (46 minute flite from FLL -Miami area).
Cuba has almost no wifi. It is a POOR country. No cell phone stores I saw, altho there is cell service available, to some extent.
Altho TMobile US has free intl roaming in 140+ countries, Cuba isn't one of them. Incoming/outgoing calls $2/min, 50 cents outgoing text (incoming free) and $2/mb for data.
Went thru total wifi/cell withdrawal for 5 days!

Upon return - learned that Digicel sells a prepaid card for roaming in Cuba. $25 for 100mb of data. They have other offers as well.
CubaRoamingHelp@digicelgroup.com or call 1-407-499-2822.

Also sold on Amazon.