Take a closer look at Google Cardboard (pictures)

Meet Google Cardboard. While there isn't all that much to it, this little box is a $30 gateway to the world of VR -- just add an Android or iOS smartphone.

Cardboard folds up into a neat, compact package. This is the second version of Google Cardboard, designed to fit larger phones.

You'll look through these lenses when the package is unfolded.

Cardboard's instructions are stamped on the front lip. It's not very complicated: just fold the eyepiece out, and snap the velcro pieces together.

When fully unfolded, the wings on either side of the lenses do a good job of blocking out ambient light.

See that little nub in the center? It taps on your phone's display whenever you need to interact with an app.

Press this trigger up top to activate the nub.

Cardboard works with Android or iOS devices -- you just need to download the Cardboard app, or one of the many Cardboard-compatible apps that are available.

Sure, it doesn't look like much. But this $30 contraption is a fun, accessible way to experience virtual reality, and share it with your friends.