Long setting countdown time: 999 days, 23 hours, 59 minutes and 59 seconds. Upgraded version: bigger size. LCD screen size: 13.8 cm x 4 cm / 5.4 x 1.6 in. 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 clock number "hour" starts flashing. Press UP/START or DOWN to adjust that particular number. Keep pressing CLOCK to set minutes and seconds. Press CLOCK again to start. In the CLOCK mode, press the DOWN button to switch between 12 and 24 hour systems. How to set countdown time: Hold the SET button until a number starts flashing. Push the SET button to navigate to the number you want to change. Press UP/START or DOWN to adjust that particular number. Press and hold UP/START or DOWN to change the number quickly. Keep pressing SET until the screen stops flashing. Press the UP/START button to start or pause the countdown. Press and hold the UP/START and DOWN buttons at the same time to reset to 0. Requires: Internal 2 x CR2032 batteries (included). Color: black Material: ABS Size: approximately 15.5 x 5.7 x 1.1 cm Package Contents: 1 x Digital timer clock Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. Measurement allowed error is +/- 1-3 cm.