Long setting countdown time: 999 days, 23 hours, 59 minutes and 59 seconds. Upgraded version: bigger size. LCD screen size: 13.8cm x 4cm / 5.4 x 1.6in. It will alarm for sixty seconds when arriving at your set number. With clock function. You can switch between 12 and 24-hour systems. Easy to set. Two ways to place it. With magnet back and movable bracket. Wide application: vacation, wedding, new baby, retirement, meeting, study, and so on. How to set clock: Hold the CLOCK button until the hour starts flashing. Press UP/START or DOWN to adjust the number. Keep pressing CLOCK to set minutes and seconds. Press CLOCK again to confirm. In CLOCK mode, press the DOWN button to switch between 12 and 24-hour formats. How to set countdown time: Hold the SET button until a number starts flashing. Press SET to move to the digit you want to change. Press UP/START or DOWN to adjust the number. Continue pressing SET until the screen stops flashing. Press UP/START to begin or pause the countdown. Press and hold UP/START and DOWN buttons together to reset to zero. Requires: 2 x CR2032 batteries (included) Color: black Material: ABS Size: approximately 15.5 x 5.7 x 1.1cm Package Contents: 1 x Digital timer clock Note: Light and display differences may cause slight color variation between the image and actual item. Measurement may vary by +/- 1-3cm.