GearNews - Lume Cube
It measures 38mm on all sides, and its LEDs are said to emit up to 1500 lumens of either flash or continuous light. Up to five units can be synced together and controlled manually or via Bluetooth using the free Lume Cube app. The cubes come in either gunmetal grey, black or silver, are depth-rated to 30m and have a quarter-tripod mount. Price is US $80 each.