Seiko Astron The worlds first GPS solar watch. Seiko has, once again, has set a new world standard in watchmaking. Crafted for the world travellers, the Seiko Astron syncs with the satellites and adjusts to your time zone at the touch of a button. And, by taking all the energy it needs from light alone, it never needs a battery change. When the watch connects with one or more GPS satellites, it re-sets the time to a precision of one second every 100,000 years. Advanced functionality highlighted by features such as high-speed time zone adjustment, time transfer and more in a modern design.