SISTEM BLACK (SUTB400) is a beautiful black and white map of the stars. It shows a universe revolving around a single, central point of light, a mirror of our solar system. Six red points representing 6 of the movement's 19 rubies glow in the darkness of infinite space, framed by a concentric array of white lights—a harmonious star-map of time. And there's more—the map has a flip-side: Turn SISTEM BLACK over, and the universe is suddenly a work of optical art, a swirling black and white vortex that captures and captivates the eye. The transparent crystal oscillating weight revolves and reveals the wonder of a mechanical microcosm that turns on a single, central screw. SISTEM51 has no need for a battery—it's powered by the person who wears it, so it features an ' automatic ', or 'self-winding' movement.