The STW515 is a digital stopwatch with an integrated alarm function. It offers the option of choosing between a 12 or 24-hour format and has a programmable alarm with an hourly signal. It also offers three different modes: running time measurement, split time measurement and a timer that can be used for two athletes. A practical backlight makes it easier to use in the dark or in poorly lit environments and switches off automatically after five seconds. The integrated calendar shows the current day, month and day of the week.