This is driver version 6.3.9600.30174 for the Asus USB Mass Storage Device. The USB storage from Asus is in actual fact a Realtek Card reader. Asus marketed this under their own brand for a while. You can find the driver listed below.
This USB storage device form ASUS is the “Realtek PCIE CardReader”. You can download this below and it will run on most operating systems. Note that is is both for a 32bit and 64bit system and both are in the same file.