If you purchased our downloadable GPS maps, and want to transfer it to your GPS unit onto an SD Card, you can either purchase an SD Card or overwrite your old T4A GPS Maps sd card if you have one:

• Recommended size:
  • Newer Garmin devices work seamlessly with 32GB and 64GB SD cards. However, we also tested a 64GB SD card on much older models, such as the Nuvi 500, and the maps displayed perfectly there as well.
  • We use SD Cards in sizes ranging from 16GB to 64GB to write our GPS Maps on.

• Formatting an SD Card: (VERY IMPORTANT)
  • It must be formatted to FAT or FAT32. Either will work, but the recommended option is FAT32.