wind up timer are cute and beautiful with cartoon design, which greatly improves children's time management concepts such as cooking, baking, reading, homework, jogging, homework, special needs and more.wind up timer has a built-in 70db alarm clock. When the time is up, the bell will ring immediately. It gives you more control over your time. It will stop a few seconds after the bell rings.wind up timer is mechanical and needs to be wound up. If you do not follow the instructions, the timer will not sound when the time is over. For example, it takes 5 minutes to boil an egg. In the first step, you need to turn the timer clockwise, from 0-5-10-15 to 20-30-40-55. Note :(the hands end at 55 minutes) step 2: turn the timer counterclockwise from 55-40-30-20-15-10-5. Note :(the pointer ends at 5 minutes). Step 3: After 5 minutes, the timer will sound.Please follow the instructions or there will be no sound.wind up timer are made of high quality materials and are strong and durable. Dimensions 2.6 inches by 2 inchesEgg timers are mechanical, with a ticking sound during use. After the timer rings, the ticking will continue for a few seconds and then stop. Those who do mind please think carefully before buying.