Features: 1. Power-off function: The device can be fully powered off, and the clock retains settings without needing to be reset. 2. Mute function: Enables silent operation for use in quiet environments. 3. Time and date display: Shows year, month, day, hour, minute, second, and weekday; supports 12-hour and 24-hour formats. 4. Stopwatch: Triple-line display with lap memory storage; accuracy up to 0.01 seconds; maximum timing duration: 9 hours, 59 minutes, 59 seconds. 5. Performance metrics: Displays fastest, slowest, and average lap times. Memory data can be scrolled forward and backward. All functions are intuitive and easy to operate. 6. Countdown timer: Adjustable countdown with maximum duration of 9 hours, 59 minutes, 59 seconds. 7. Daily alarm: Quick on/off control for alarm functionality. 8. Metronome: Adjustable tempo from 5 to 320 BPM (in increments of 5); includes count-up timing function. Specifications: Model: YS810 / YS830 / YS860 / YS8100 Color: White / Black Display: Triple-line LCD showing up to 10 / 30 / 60 / 100 laps Material: ABS plastic housing Battery: Built-in CR2032 coin cell Display size: 35 x 23.5 mm (1.38 x 0.93 in) Product dimensions: 75 x 62 x 21 mm (2.95 x 2.44 x 0.83 in) Weight: 70 g