This is assembled the IN-12A in-12B Nixie Tubes Clock Power: 5V/0.3A, (5V adapter, or USB from PC, or powerbank - not included) Hours, minutes, 24 time display Tubes are tested and comes from NOS (included) Built-in battery socket, time backup during power interruptions (battery CR 1220 3V, not included) RGB backlight 9 colors Watch size ~ 4.4 * 1.42 * 1.77 inches .