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 12/24-hour format switchable. 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: Press and hold the CLOCK button until the hour digits flash. Use UP/START or DOWN to adjust the hour. Press CLOCK again to cycle through minutes and seconds. Press CLOCK once more to confirm. In clock mode, press DOWN to switch between 12-hour and 24-hour formats. How to set countdown time: Press and hold the SET button until a number flashes. Use SET to navigate to the desired digit. Adjust using UP/START or DOWN; hold the button for fast change. Continue pressing SET until flashing stops. Press UP/START to begin or pause countdown. Press and hold UP/START and DOWN together to reset to zero. 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. Only the above items included; other products not included. Note: Lighting and display differences may cause slight color variations between image and actual item. Measurement error allowed within +/- 1-3 cm.