The electrical current in Cuba is mostly 110 volts AC (the same as in the U.S.). Many recently built hotels also have 220-volt AC current. Some have both 110v and 220 v. We recommend bringing a multi-adapter which will ensure that you can plug in and charge any devices in your room. You may need a power converter if your appliance or device doesn't provide a range of currents such as 110-240v or 120-240v. If the adapter doesn't say 240v on it somewhere and you have to plug it in to a 220v outlet, the unit may not work. Most smart phones and other portable devices have internal transformers that allow you to plug in the device in any country. You just need the correct wall adapter.