Long countdown setting time: 999 days, 23 hours, 59 minutes, and 59 seconds. Upgraded version with larger size. LCD screen size: 138 cm x 4 cm / 54 x 1.6 in. Sounds an alarm for sixty seconds when the set time is reached. Includes clock function. Switchable between 12-hour and 24-hour formats. Easy to set. Can be placed in two ways. Features a magnetic back and is portable. Wide range of applications: vacation, wedding, new baby, retirement, meetings, study sessions, and more. How to set the clock: Press and hold the CLOCK button until the hour digits flash. Use the UP/START or DOWN button to adjust the hour. Press CLOCK repeatedly to set minutes and seconds. Press CLOCK again to confirm. In clock mode, press the DOWN button to switch between 12-hour and 24-hour formats. How to set the countdown timer: Press and hold the SET button until a number starts flashing. Continue pressing SET to navigate to the digit you wish to change. Use UP/START or DOWN to adjust the selected value. Pressing and holding UP/START or DOWN changes the number quickly. Keep pressing SET until the display stops flashing. Press UP/START to begin or pause the countdown. Press and hold both UP/START and DOWN buttons simultaneously to reset the timer to zero. Requires 2 x CR2032 batteries (included). Color: black. Material: ABS. Size: approximately 155 x 57 x 11 cm. Package includes: 1 x Digital timer clock. Only the items listed are included; other items are not part of the package. Note: Lighting and display differences may cause slight variations in the color shown in images compared to the actual product. Measurement may vary by +/- 1-3 cm.