SD Card reader module


I had one SD Card Reader module like this one:

I would to like to know why it has two rows of male pins and how to use them.


Rocky has this on his WIKI about this product:

But I don't understand it either! How could it do this??
---------------------( COPY )---------------------
Break out board for standard SD card and Micro SD (TF) card
Contains a switch to select the flash card slot
Sits directly on a Arduino
-----------------( END COPY )----------------------
Ask them at:
Or email Rocky Himself at:

I used to live close to these guys in Nanshan.

Yeap, I think our doubts are near the same.

I have the same results connecting the module using the left or right row, or alternating. What for are they?