Usage Tips:Long setting countdown time: 999 , 23 hours, 59 minutes and 59 seconds. Upgraded version: bigger size. LCD screen size:13.8cmx4cm/5.4x1.6in. It will alarm for sixty seconds when arriving at your setting number. With clock function. You can switch between 12 and 24 hours . Easy to set. Two ways to place it. With magnet back and movable bracket. Wide application: vocation, wedding, baby, retirement, meeting, study, and so on. How to set clock: Hold the CLOCK button see the clock number "hour" start flashing. Press UP/START or DOWN to adjust that particular number. Keep hitting CLOCK to set minutes - seconds. Press CLOCK again to start. In the CLOCK mode, press the DOWN button to switch between 12 and 24 hours . How to set countdown time: Hold the SET button see a number start flashing. Push the SET button get to the number you want to change. Press UP/START or DOWN to adjust that particular number. /START or DOWN, the number will change quickly. Keep hitting SET until the screen stops flashing. Press the UP/START button to start or pause the counting down. Press and hold the UP/START and DOWN buttons at the same time to reset to 0. Requires: Internal 2 x CR2032 batteries (Included) Colour: black Material: ABS Size: about 15.5x5.7x1.1cm Package Contents: 1 * Digital timer clock Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.