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). Sounds an alarm for sixty seconds when the set time is reached. Features a clock function with the ability to switch between 12-hour and 24-hour formats. Easy to set. Can be placed in two ways: with magnetic back and movable 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 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-hour and 24-hour formats. How to set countdown time: Press and hold the SET button until a number starts flashing. Continue pressing SET to navigate to the digit you wish to change. Use UP/START or DOWN to adjust 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 above content is included; other items are not part of the package. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.