Features: 1. Shutdown function: power can be turned off and the clock does not need to be reset (most stopwatches on the market currently do not have a shutdown function). 2. Key mute function: It can be muted and used in quiet situations. 3. Time and calendar function: displays year, month, day, hour, minute, second, week, with 12/24 hour system optional. 4. Stopwatch function: 3-row display, segmented memory storage, precise value up to 1/100 seconds, maximum time is 9 hours 59 minutes 59 seconds. 5. Fastest, slowest, and average values can be viewed. When searching memory data, you can scroll up and down. Each function is easy to use. 6. Countdown function: can set countdown and time count functions. Maximum countdown time is 9 hours, 59 minutes and 59 seconds. 7. Daily alarm clock function: allows quick on/off control of the alarm. 8. Metronome function: beat frequency can be selected from 5 to 320 beats per minute (in multiples of 5) and includes time counting function. Specifications: Model: YS810/ YS830/ YS860/ YS8100 Color: white/ black Display: 3-row display with 10/30/60/100 lap memory Material: ABS plastic shell Battery: built-in CR2032 button battery Display size: 35 x 23.5mm / 1.38 x 0.93 inches Product size: 75 x 62 x 21mm / 2.95 x 2.44 x 0.83 inches Gross weight: 70g