Its called the Ring Clock, and is meant to be a time telling device worn on one of your fingers. It allegedly uses ultra-thin mono-color LEDs and a ultrathin rechargeable lithium polymer battery (Wearable Technology)
A cool guide to ring metals. My husband picked out his engagement/wedding band. It is two tone white and yellow gold with a trio of tiny square diamonds. Classic, masculine, and nice-looking. I love that our rings complement each other.