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. Alarm sounds for sixty seconds when the set time is reached. Includes clock function with switchable 12-hour and 24-hour format. Easy to operate. Two placement options: magnetic back and adjustable stand. Suitable for various occasions such as vacation, wedding, baby, retirement, meeting, study, and more. How to set the clock: Hold the CLOCK button until the hour digits flash. Use UP/START or DOWN to adjust the hour. Press CLOCK again to set minutes and seconds. Press CLOCK once more to confirm. In clock mode, press DOWN to switch between 12-hour and 24-hour format. How to set countdown time: Hold the SET button until a number starts flashing. Press SET repeatedly to select the digit to change. Use UP/START or DOWN to adjust the selected digit. Hold the button for faster adjustment. Continue pressing SET until the display stops flashing. Press UP/START to begin or pause the countdown. To reset to zero, press and hold UP/START and DOWN simultaneously. Requires 2 x CR2032 batteries (included). Color: white. Material: ABS. Size: approximately 15.5 x 5.7 x 1.1 cm. Package includes: 1 x Digital timer clock.