Dentist's First Recommendation: Hourglass Toothbrushing Kids' two-minute brushing time is designed according to scientific knowledge and does not make children feel that the time is too long and lose interest in brushing their teeth. Brushing Assistant: Fun color themes, cute tooth shapes, and cartoon smileys make children love brushing their teeth. Safety Material: Made of durable PVC, high-quality borosilicate glass, non-toxic sand, very safe for children. After testing, the base at both ends is not easy to pull off and break, which is an ideal timer for children to brush their teeth. Multiple Uses: Very suitable for children to brush their teeth, can also be used during study or play to help children do things more efficiently and improve the concept of time. A great gift for kids and friends Hourglass Instructions: You will receive 2 pieces of 3-minute hourglass. Please shake the hourglass to loosen all the sand and turn it over on the table to start the clock. For inaccurate measuring devices, please allow a 10% time deviation