The Nintendo Switch branded Micro SD Cards are now available in the North American region. There are currently three different size options: 16 GB, 32 GB and 64 GB. If you are interested, you can purchase the cards with the following links:
You can also check out what one of the Micro SD Card looks like with the image placed just below this paragraph.
For the uninformed, the Nintendo Switch Micro SD Cards as a way to store digital videogames. The system comes pre-installed with 32 GB of flash storage memory, which can quickly be depleted due to the file sizes of downloadable games, downloadable content and patch updates. In fact, more and more games, such as Doom and NBA 2K18, are requiring Micro SD Cards in order to get the full experience.
Nintendo previously stated that the Switch will support external hard drives in the future. With that said, the USB HDDs will mostly only be used in docked mode, meaning that you will still need Micro SD Cards when playing on the portable unit.
So, if you are looking into adding more space for your Switch, then you might want to check out the Nintendo Switch branded Micro SD Cards from Hori.