Long countdown time setting: up to 999 days, 23 hours, 59 minutes, and 59 seconds. Upgraded version with larger LCD screen: 13.8 cm x 4 cm (5.4 in x 1.6 in). Audible alarm sounds for 60 seconds when the countdown reaches zero. Built-in clock function with 12-hour and 24-hour time format selection. Simple and intuitive time and countdown setup. Dual mounting options: built-in magnet back and adjustable stand. Versatile use: suitable for vacations, weddings, birthdays, retirements, meetings, study sessions, and more. Clock setup instructions: - Press and hold the CLOCK button until the hour digits flash. - Use UP/START or DOWN buttons to adjust the hour. - Press CLOCK again to move to minutes, then seconds. - Press CLOCK once more to confirm and start the clock. - In clock mode, press DOWN to toggle between 12-hour and 24-hour display. Countdown setup instructions: - Press and hold the SET button until a digit flashes. - Press SET repeatedly to navigate between days, hours, minutes, and seconds. - Use UP/START or DOWN to adjust each value; hold the button for rapid adjustment. - Press SET until flashing stops to save settings. - Press UP/START to start or pause the countdown. - Press and hold UP/START and DOWN simultaneously to reset to zero. Power: 2 x CR2032 batteries (included). Color: black/white. Material: ABS plastic. Dimensions: approximately 15.5 cm x 5.7 cm x 1.1 cm. Package includes: 1 x digital timer clock. Note: Screen lighting and display settings may cause slight color variation between the image and the actual product. Measurement tolerance: ±1–3 cm.