The Translation Picker block allows your end users to choose their language from a dropdown of Translations added by an administrator. For more information on Translations see Translations help page.
When editing a Translation Picker Block you can set the name and tags as well as the label of the select box shown to the end-user and any help text to display below the input. You can also set a default Translation to load before the user has chosen their preference.
As with other Blocks, you can add any custom CSS you wish on the CSS tab and preview your changes on the Preview tab.