Vita 3G SD Storage Expander for PS Vita 3G (PCH-1100)

This is the Vita 3G SD Storage Expander. It's an internal storage card for the Playsation Vita 3G by replacing the modem module and does away with the need of using Vita memory cards and use a standard MicroSD Card. 

If you're familiar with the PSVSD then you'll be familiar with this. 

To setup your vita to read the card, it is done the same way a PSVSD is setup. 

You do need to have a hacked Vita 3G to begin with. Go to vita.hacks.guide for a more up-to-date guide if you don't have a hacked Vita 3G already.
 
And then go to psvsd.henkaku.xyz for a guide on how to get your card to read, the important step there being step 3. Step 1 and 2 is just hacking your vita, but is an older guide.