this is to get extra storage for a tablet/smartphone without having tu plug/unplug oftenly a "large" µUSB key the SD card part stick on the back of the device with bluetack (choose this because it is not too much not too few sticky, and you can get it yourself if you lose some) card part shouldn't bother you on the back of the device as it is 25x15x1,5mm (K'ollé>collé=stuck)