I got one for Christmas but it doesn't work with my non-Mac ultrabook.
Link to manufacture:
http://www3.pny.com/128GB-StorEDGE-F...P3408C591.aspx
Doubles your storage space
Plugs in to your MacBook’s SDXC slot and stays in: a semi-permanent storage solution. Product sits flush against your notebook.
StorEDGE is ideal for:
13-inch MacBook Air
MacBook Pro
15-inch MacBook Pro with Retina display
Capacity:
128GB
Stock Photos:
Picture I took:
SOLD