I have for my loudspeaker transmits from EXPOWER ST7220 requires this adapter because it has only a USB-A connector. About this he is even charged with a USB-A to USB-A plug-plug cable and a microUSB A to USB A male to male cable other devices can be charged via these. Now I think it's not so great take tens of different cables and so I ordered this adapter. It works great.
Whether a data transmission works so that I can for lack of devices that may be connected with a USB-A to USB-A cable, not tell.
The processing of the adapter is very good, since there is nothing to complain about. I hereby commend this adapter for the purpose I have described.