Watch this movie...
Isn't amazing? It looks just like a future-oriented ring. The gadgets are reducing people's action or movement one after another.
It is a little bigger as a ring called "Ring".
When you write "TV" in the air, then you can turn on the TV.
If you write $12 in the air, the payment will be completed.
When people who wear the same rings shake hands, then they can exchange the information.
- Source from danshihack.com