This is the best portable external hard-disk because of its smart look and fast performance. It is only 2.5in size, small enough to be carried in coat pocket with weight of 160g. WD passport ultra is provided with a carrying pouch to protect it against accidents drops. It has a ability to backup files from Dropbox to the passport ultra. The back up software used is WD smartware. It comes with 3 years warranty to boost our confidence that no problem will occur and in case any problems occur the 3 years warmth will help.