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 12-hour and 24-hour format switching. 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 start flashing. Use UP/START or DOWN buttons to adjust the value. Press CLOCK repeatedly to set minutes and seconds. Press CLOCK again to confirm and start. In clock mode, press the DOWN button to switch between 12-hour and 24-hour formats. How to set countdown time: Hold the SET button until a number starts flashing. Press SET repeatedly to select the digit to adjust. Use UP/START or DOWN buttons to change the value. 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 both UP/START and DOWN buttons 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