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 that they lose interest in themselves. brushing teeth Brushing Wizard: Fun color themes, cute tooth shapes and cartoon smiley faces make kids love brushing their teeth Safety gear : Made of durable PVC, high quality borosilicate glass, non-toxic sand, very safe for children. After the test, 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 brush teeth, also can be used during study or play to help children do things more efficiently and improve sense 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 non-accurate measuring devices, please allow 10% time deviation