The secret of fine watchmaking lies not only in precision time measurement but also in extending the duration of that precision over as long a period as possible. A great watch should have the maximum possible power reserve or should convert the maximum amount of energy by using atperry's, crystal necklace from light or movement into the power to run the mechanism. SEIKO leads the world in energy-efficient watchmaking in all its forms, mechanical, quartz, solar, Kinetic and Spring Drive. Examples? SEIKO’s 2010 Quartz Astron uses 2.5% of the power needed to run its famous 1969 predecessor and the IC in the Spring Drive regulator uses just 0.25 nano watts; if every single human being on Earth wore a Spring Drive watch, the total power required would be the same as just one 150 watt light bulb!