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 year, retirement, meeting, study, and so on. How to set clock: Hold the CLOCK button until you see the clock number "hour" start flashing. Press UP/START or DOWN to adjust that particular number. Keep hitting CLOCK to set minutes - 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 you see a number start flashing. Push the SET button until you get to the number you want to change. Press UP/START or DOWN to adjust that particular number. Hold UP/START or DOWN, the number will change quickly. Keep hitting SET until the screen stops flashing. Press the UP/START button to start or pause the counting down. 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/white Material: ABS Size: about 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 shooting and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.