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 options. Easy to set and operate. Two placement options: magnetic back and adjustable stand. Suitable for various ocns such as vacations, weddings, retirement, meetings, studying, and more. How to set the clock: 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 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 formats. How to set the countdown timer: Hold the SET button until a number starts flashing. Press SET repeatedly to cycle through days, hours, minutes, and seconds. Use UP/START or DOWN to adjust the flashing digit. Hold the button to change quickly. Continue pressing SET until the display stops flashing to save settings. Press UP/START to begin or pause the countdown. To reset, press and hold both UP/START and DOWN buttons simultaneously. Requires 2 x CR2032 batteries (included). Color: black/white Material: ABS Size: approximately 15.5 x 5.7 x 1.1 cm Package Contents: 1 x Digital timer clock Note: Light exposure and screen differences may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.