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 reaching the set time. With clock function. You can switch between 12 and 24-hour formats. Easy to set. Two ways to place it: with magnetic back and movable bracket. Wide application: vacation, wedding, new baby, retirement, meeting, study, and more. How to set the clock: Hold the CLOCK button until the hour starts flashing. Press UP/START or DOWN to adjust the number. Press CLOCK repeatedly 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 the SET button to navigate to the digit you want to change. Press UP/START or DOWN to adjust the number. Holding the button changes the number quickly. 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 simultaneously to reset to zero. Requires: 2 x CR2032 batteries (included) Color: white Material: ABS Size: approximately 15.5 x 5.7 x 1.1cm Package Contents: 1 x Digital timer clock Only the above package content; other items are not included. Note: Lighting and display differences may cause slight color variation between the image and the actual item. Measurement error allowed is +/- 1-3cm.