Twist One Button Operation DSi simple that old grandma and 5 year old kids can use it easily. Silver button and black body, just twist the button to set the time, press to start or stop. The light digital dims 5 seconds and off in another 5 seconds, which can last battery life. With the magent on the back, you can stick to the classroom whiteboard, stove, task, student tablet, iron wall, refrigerator, gym or any other steel place. help students focus on study, time management for shower, games, etc., teacher organization for classroom, mothers cooking, baking, cooking eggs Large 3-inch screen with constant brightness function. Constant luminous digits make it easy to read from a long distance. Even in a large meeting room, classroom or large kitchen, exercise room. 3 level alarm sound mode, can be silent, normal or up to 90 dB. Does not beep unnecessarily when setting the timer. Can hear this alarm in another room, no longer worry about overcooking. The flashing LED digital number will remind you of the arrival time in silent mode. Features: Material: electroplating button + ABS. Volume gears: mute 0db/normal 6070db/loud gear 8090db. Voltage: 4.5V Size: Diameter 3 INCH * 1 INCH Installation: for hanging or standing Operating temperature: 050 degrees Timeout range: 099 minutes 55 seconds Batteries: 3 AAA 1.5V batteries (not included)