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 options. Easy to operate. Two placement options: magnetic back and adjustable stand. Suitable for various occasions such as vacation, wedding, newborn, retirement, meetings, study sessions, and more. How to set the clock: Press and hold the CLOCK button until the hour digits flash. Use the UP/START or DOWN button to adjust the hour. Press CLOCK repeatedly to cycle through minutes and seconds. Press CLOCK again to confirm and start. In clock mode, press the DOWN button to switch between 12-hour and 24-hour formats. How to set the countdown timer: Press and hold the SET button until a number begins to flash. Press SET repeatedly to select the digit you wish to change. Use the UP/START or DOWN button to adjust the selected digit. Holding the button changes the number quickly. Continue pressing SET until flashing stops. 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 Material: ABS Size: Approximately 15.5 x 5.7 x 1.1 cm Package Contents: 1 x Digital timer clock (Other items not included) Note: Lighting and display differences may cause slight color variation between the image and the actual item. Measurement error allowed within +/- 1-3 cm.