Thanks. I tried to install this on Mapsource 6.15.3. I was not successful as the p[rogram wants me to unlock this online. When I go to the online site at garmin it asks for the 'KEY' or 'PRODUCT CODE'. I tried the unlock code from Jetmouse 1.5 but Garmin says it is not the right code. What am I doing wrong? I have however got it to work on my GPS Nuvi350 unit.