Denny Crane, Esq.
It feels odd to give 5 stars to something that disappeared into a piece of electronics, but to be fair, it works as promised, and there is nothing wrong with it.  I use it to store the digital map for my Garmin 810 bike GPS/computer.  The file is about 4Gb in size. The map loads quickly in the Garmin, and I have not had a problem with entering a bike route or navigating one.  I have taken it out twice, a 42 mile ride and a 60 mile ride, and it worked flawlessly both times.  'Nuff said.