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 formats. Easy to set and 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 display starts flashing. Use UP/START or DOWN buttons to adjust the hour. Press CLOCK again to move to minutes and then seconds. Press CLOCK once more to confirm and start. In clock mode, press the DOWN button to switch between 12-hour and 24-hour format. How to set the countdown timer: Hold the SET button until a number starts flashing. Press SET repeatedly to cycle through digits you wish 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. 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