Long setting countdown time: 999 days, 23 hours, 59 minutes, and 59 seconds. Upgraded version with larger size. LCD screen size: 13.8 cm x 4 cm / 5.4 x 1.6 in. Alarms for sixty seconds when the set time is reached. Includes clock function with 12-hour and 24-hour format switching. Easy to set. Two placement options: magnetic back and adjustable bracket. Wide application for vacation, wedding, new baby, retirement, meeting, study, and more. How to set the clock: Press and hold the CLOCK button until the hour starts flashing. Use the UP/START or DOWN button to adjust the value. 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 countdown time: Press and hold the SET button until a number flashes. Press SET repeatedly to select the digit to adjust. Use UP/START or DOWN to change the value. Press SET repeatedly 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 to zero. Requires 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 items listed are included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3 cm.