......
You say you can't test it. In fact you can. Put the microSD in your nüvi 1490 and scroll the map to Costa Rica. Zoom in at any location (for instance San Jose) and you'll see the map shows more and more details as you zoom in further.
Some units are even capable of simulating a route. Off the top of my head, I'm not sure if that also applies to the nüvi 1490. No time now to check, but you can find out yourself by checking the instruction manual. If capable, you could simulate a route somewhere within Costa Rica and that way prove for yourself the map on your microSD works. :smile: