Introduction - If you have any usage issues, please Google them yourself
digital tube top three shows a stopwatch, 000 to 999 to 1/100th of a second speed, a separate keyboard is pressed when the stopwatch stopped, loosen hand stopwatch continues to run. (using the timer design).
On the basis of the above questions, with the other three independent keyboard to achieve press the first time to stop, according to the first two hours when the start, according to the first three is the number of data cleared scratch.