It has a rugged water-resistant to and shock resistant case. THe water resistance level is to IPX7 which means it can be immersed in water of 1m depth for up to 30 minutes. Mode A:Stopwatch: The stopwatch can count up to 24 hours. Timing to 1/100th sec for the first 30 minutes. Then in 1 second intervals.With START, STOP, (TIME OUT) RESUME or RESET function and CUMULATIVE SPLIT TIME function. ONE/TWO FAST FINISH:Press the split button to take the time of competitor 1. Press the stop button then the split button to show the time of competitor 2. Mode B: TIME OF DAYMode C: ALARM SET: Use this function to set the alarm. Good for rugged single event timing and water sports and events where cumulativesplit times are required. Suitable for professional use Battery CR2032 Size Length: 80mm, Width: 70mm Depth: 20mm, Digits: 15mm Features Water Resistant to IPX7, Backlight. .