It came with a little envelope in which I'm supposed to store the card when not in use. The envelope's interior has been metalicized.
Keep the card in its protective sleeve at all times unless you are presenting it at the border. This will help prevent the RFID chip from being read by an unauthorized reader.
Using duct tape and aluminum foil, I have created a prototype of a similar safeguard for my other identities. Seems effective, albeit hard to see out of.