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. Wide application for vacation, wedding, birthday, retirement, meeting, study, and more. How to set the clock: Hold the CLOCK button until the hour starts flashing. Use UP/START or DOWN to adjust the value. Press CLOCK repeatedly to set minutes and seconds. Press CLOCK again to confirm and start. In clock mode, press DOWN 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. Hold the button for faster changes. Continue pressing SET until the display stops flashing. Press UP/START to begin or pause the countdown. To reset to zero, press and hold 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 shooting and different displays may cause slight color variations between the image and the actual item. Measurement allows an error of +/- 1-3 cm.