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. Alarm sounds for sixty seconds when the set time is reached. Includes clock function with 12-hour and 24-hour format switching. Easy to set and operate. Two placement options: magnetic back and adjustable stand. Suitable for various occasions such as vacation, wedding, newborn, retirement, meetings, and study sessions. How to set the clock: Hold the CLOCK button until the hour digits start flashing. Use the UP/START or DOWN button to adjust the hour. Press CLOCK again to move to minutes and seconds. Press CLOCK once more to confirm and start. In clock mode, press the DOWN button to switch between 12-hour and 24-hour formats. How to set countdown time: Hold the SET button until a number starts flashing. Press SET repeatedly to select the digit to adjust. Use UP/START or DOWN to change the value. Hold the button for faster adjustment. Continue pressing SET until the display stops flashing. Press UP/START to start 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 Note: Light and display differences may cause slight color variation between the image and the actual item. Measurement may vary by +/- 1-3 cm.