Long setting countdown time: 999 days, 23 hours, 59 minutes and 59 seconds. Upgraded version with larger size. LCD screen size: 13.8cm x 4cm / 5.4in x 1.6in. Alarm sounds for sixty seconds when the set time is reached. Includes clock function with switchable 12-hour and 24-hour formats. Easy to set and operate. Two placement options: magnetic back and adjustable stand. Wide application for vacation, wedding, retirement, meetings, study, and more. How to set the clock: Hold the CLOCK button until the hour display starts flashing. Use UP/START or DOWN buttons to adjust the hour. Press CLOCK again to cycle to minutes and seconds, adjusting as needed. Press CLOCK once more to confirm and start. In clock mode, press the DOWN button to toggle between 12-hour and 24-hour formats. How to set countdown time: Hold the SET button until a number begins flashing. Press SET repeatedly to select the digit to change. Use UP/START or DOWN buttons to adjust the selected digit. Hold the button for faster changes. Continue pressing SET until the display stops flashing. Press UP/START to begin or pause the countdown. To reset to zero, press and hold both UP/START and DOWN buttons simultaneously. Requires 2 x CR2032 batteries (included). Color: black/white Material: ABS Size: approximately 15.5 x 5.7 x 1.1 cm Package Contents: 1 x Digital timer clock Note: Light reflection and display differences may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.