Produced since 1982, based on original Eterna caliber 1427. Considered a "workhorse" movement in watch industry. Manual wind version available as caliber 2804-2
Automatic watches wind using wearer's natural motion, eliminating manual winding. Mainspring stores energy for about two days when fully wound. Modern watches can be manually wound by turning crown
Pendulum clock was invented by Christiaan Huygens in 1656, inspired by Galileo's work. First pendulum clock design by Galileo was incomplete in 1649. By 1659, clocks were manufactured in France and England. Clockmakers developed anchor escapement to reduce swing angle to 4-6°
Stopwatch measures time between activation and deactivation. Stop clock is digital version for distant viewing. Manual timing uses button presses, automatic timing uses sensors
Watches evolved from portable spring-driven clocks in 16th century Europe. Peter Henlein is credited as inventor of first wearable timepieces. Early watches were cylindrical, ornate, and worn as pendants. Men started wearing watches in pockets in 17th century
Citizen wins in accuracy and longevity, Seiko excels in style and design. Citizen specializes in quartz movements, Seiko focuses on mechanical ones. Citizen's Eco-drive technology leads in solar-powered watches. Citizen watches typically last longer than Seiko's