Powered by 1 AA battery ( not included) with up to 200 days of battery life for long lasting Motivational color changes encourage children ' s engagement by providing visual progress feedbacks during tasks Simple operations with easy rotation to set time from 1 60 minutes, perfect for kids to develop time management skills during study or play Visual time management features rainbow colorful designs that clearly shows time passing, helping children understand time concepts and improve focus Versatile usage for homework, reading, or playtimes limits to help parents organize children ' s daily activities effectively