1-second stopwatch Measuring capacity: 11:59'59 Measuring mode: Elapsed time Date display Regular timekeeping Analog: 3 hands (timekeeping hour and minutes, stopwatch seconds 3 dials (timekeeping seconds, stopwatch hours and minutes) Accuracy: ±20 seconds

1-second stopwatch Measuring capacity: 11:59'59 Measuring mode: Elapsed time Date display Regular timekeeping Analog: 3 hands (timekeeping hour and minutes, stopwatch seconds 3 dials (timekeeping seconds, stopwatch hours and minutes) Accuracy: ±20 seconds per month Approx. battery life: 2 years on SR927W Size of case / total weight EF-539SG : 53.5 X 48.5 X 11.5 mm / 198 g