The Casio SDB100 Running watch has a 10 Year Battery, the SDB100 Runner Series is not only powerful; it's also eco-friendly too. This long lasting power will translate into years of reliable training data. With a front-button activated 1/100 Second Stopwatch with 60-Lap Memory, Pace Signal and Distance Calculation, you won't want to leave for your next run without it. 50M Water Resistant Auto LED Light with Afterglow Dual Time 4 Daily Alarms and 1 Snooze Alarm Hourly Time Signal 1/100 Second Stopwatch Measuring Units: 1/100 Second (Lower Display for the first 60 Minutes, Center Display for the first 10 Hours), 1 Second (Lower Display after 60 Minutes, Center Display after 10 Hours); 0.1 Mile or Kilometer Measuring Capacity: 99:59'59"; 99.9 Miles or Kilometers (Total Distance Covered) Measuring Modes: Elapsed Time, Lap/Split Time Memory Capacity: Up to 61 Lap/Split Numbers and Times; Total Distance Covered Input Data: Stride Length 40 to 190cm (16 to 76 inches) Pace Signal Countdown Timer Measuring Unit: 1 Second Countdown Range: 1 Minute to 100 Hours Other: Auto-repeat Function Full Auto-calendar (Pre-programmed until the year 2039) 12/24 Hour Formats Battery: CR2025 Approximate Battery Life: 10 Years.