Long setting countdown time: 999 days, 23 hours, 59 minutes, and 59 seconds. Upgraded version with larger size. LCD screen size: 13.8 cm x 4 cm (5.4 x 1.6 in). Alarms for sixty seconds when the set time is reached. Includes clock function with 12-hour and 24-hour format options. Easy to set. Two placement options: magnetic back and adjustable bracket. Suitable for various occasions such as vacations, weddings, newborns, retirement, meetings, and studying. How to set the clock: Press and hold the CLOCK button until the hour digits start flashing. Use the UP/START or DOWN button to adjust the hour. Press CLOCK again to cycle to minutes and seconds. Press CLOCK once more to confirm. In clock mode, press the DOWN button to switch between 12-hour and 24-hour formats. How to set countdown time: Press and hold the SET button until a number starts flashing. Continue pressing SET to navigate to the digit you want to change. Use UP/START or DOWN to adjust the selected value. Press SET repeatedly until the display stops flashing. Press UP/START to begin or pause the countdown. Press and hold both UP/START and DOWN buttons simultaneously to reset the timer to zero. Powered by 2 x CR2032 batteries (included). Color: black. Material: ABS. Size: approximately 15.5 x 5.7 x 1.1 cm. Package includes: 1 x Digital timer clock. Note: The actual product may vary slightly in color due to lighting and screen differences. Measurement error allowed within +/- 1-3 cm.