No battery change required & powered by all types of light. Solar cell w/high performance electricity generation. Energy-efficient movement w/long power reserve. Its blue dial features three chronograph subdials, luminous hands & markers, & date calendar. Alarm can be set on a 12-hour basis w/two small hands. Chronograph measures up to 60 minutes in 1/5 second increments w/split time measurement. Alarm hands can indicate the time in a different time zone. 100 meters water resistant. Complies with Prop 65.