Somehow, I can't get this one to work in Basecamp. I unzip the downloaded file, then put the two .img files onto my USB stick, as I normally do. When I select the map in Basecamp, I can see that Japan is marked by a blue line around it, but when I zoom in, the map isn't shown. One thing that is different from what I am used to with other maps is that there are two .img files, gmapsupp.img and gmapsupp_search.img. I don't know whether that's the reason that it doesn't work.