Features: 1. Power-off function: The device can be powered off, and the time settings are retained. 2. Mute function: Allows silent operation in quiet environments. 3. Time and calendar display: Shows year, month, day, hour, minute, second, and weekday; 12-hour or 24-hour format selectable. 4. Stopwatch function: Triple-line display with split memory storage; precision 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 up or down for review. All functions are intuitive and easy to operate. 6. Countdown timer: Configurable countdown with maximum duration of 9 hours, 59 minutes, 59 seconds. Also supports interval timing. 7. Daily alarm: Quick enable/disable functionality. 8. Metronome: Adjustable tempo from 5 to 320 BPM in increments of 5; includes timing function. Specifications: Model: YS810 / YS830 / YS860 / YS8100 Color: White / Black Display: Triple-line LCD, supports 10 / 30 / 60 / 100 lap memory Material: ABS plastic housing Battery: Built-in CR2032 coin cell Display size: 35 × 23.5 mm (1.38 × 0.93 in) Product dimensions: 75 × 62 × 21 mm (2.95 × 2.44 × 0.83 in) Weight: 70 g