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 bracket. Suitable for various occasions such as vacation, wedding, newborn, retirement, meetings, study, and more. How to set the clock: Hold the CLOCK button until the hour digits start flashing. Press UP/START or DOWN 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 countdown time: Hold the SET button until a number starts flashing. Press SET repeatedly to navigate to the digit you wish to change. Use UP/START or DOWN to adjust the selected digit. Holding the button allows fast adjustment. Continue pressing SET until the display stops flashing. Press UP/START to begin or pause the countdown. To reset, 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 Contents: 1 x Digital Clock Note: Light and screen display differences may cause slight color variation between the image and the actual item. Measurement error allowed within +/- 1-3 cm.