If you attempt to use a USB OTG drive with the phone as you would an average phone or tablet, you will find that the microUSB plug is too short to properly connect with the phone's port and that the body of the OTG drive bumps against the case of the phone due to the port being recessed and covered, which only allows USB connectors that use the standardized cable dimensions - which fit perfectly inside the recessed area where the port sits - to be used with the phone. If you want to use a USB OTG drive, you will have to get an adapter cable that takes USB female and converts it to microUSB male. StarTech has such an offering and you can get it from Amazon for a pittance.