When installing a new map release onto your device, you get prompted that there is not enough free memory on the device to install all selected countries:

Please deselect some countries you don't need at the moment to meet the available memory of the device.If you need other countries at some time you will be able to install another set of countries onto your device using the Fresh application.

Attention! The device is able to handle a memory card - but the memory card cannot be loaded with maps or other parts of the navigation system.
The memory card can be used for music or pictures only.