Ok let me tel u first about its build quality it’s not that great but good. if it will fall from your hand it will not damaged . it’s actually a USB 3. 0 hard drive and not required external power.it quite handy and comfortable to carry in your pocket. the storage is around 950 GB and also compatable for tablets via OTG cable it takes lots of powers so you have to charge your tablet Ful before using it .obviously depends on your battery.