Main Features: 8-digit calculation function. Dual Time Stopwatch (1/100 second, 24 hour counter, split included) Time alarm, time signal. Fully automatic calendar. ● Switch sound between ON/OFF Switch between 12 and 24 hour displays. Accuracy: ±30 seconds per month Battery Life: Approx. 5 years (*This is the value when you replace a new battery after purchase. The batteries that are pre-set with your watch at the time of purchase will run out in a short period of time due to the monitor battery used to check the functionality and performance of the watch built in during manufacture. )