Long countdown setting time: up to 999 days, 23 hours, 59 minutes, and 59 seconds. Upgraded version with larger size. LCD screen measures 13.8 cm x 4 cm (5.4 x 1.6 inches). Sounds an alarm for 60 seconds when the set time is reached. Includes clock function with 12/24-hour format switchable via the DOWN button. Easy to set and operate. Two placement options: magnetic back and adjustable stand. Suitable for various occasions such as vacations, weddings, baby tracking, retirement, meetings, and studying. 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 repeatedly to set minutes and seconds. Press CLOCK again to confirm. In clock mode, use the DOWN button to switch between 12-hour and 24-hour formats. To set countdown time: Press and hold the SET button until a number flashes. Press SET repeatedly to select the digit to adjust. Use UP/START or DOWN to change the value. Hold UP/START or DOWN for faster adjustment. Continue pressing SET until the display stops flashing. Press UP/START to start or pause the countdown. To reset to zero, press and hold both UP/START and DOWN buttons simultaneously. Powered by 2 x CR2032 batteries (included). Color: Black. Material: ABS. Dimensions: 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 variations between the image and the actual item. Measurement error allowance: +/- 1-3 cm.