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. Switchable between 12-hour and 24-hour formats. Easy to set and operate. Two placement options: magnetic back and adjustable stand. Wide range of applications: vacation, wedding, baby, retirement, meeting, 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, 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 countdown time: Hold the SET button until a number starts flashing. Press SET repeatedly to select the digit you want to change. Use UP/START or DOWN to adjust the selected digit. Hold the button to change quickly. 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 Contents: 1 x Digital timer clock