Dentist First Recommendation - Hourglass Toothbrushing Kids two-minute brushing time is designed in accordance with scientific knowledge and does not give children the impression that the time is too long and they lose interest in brushing their teeth Brushing Assistant - Fun color themes, cute tooth shapes and cartoon smileys make kids love brushing their teeth Safety material: 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 remove 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 effectively and improve the notion of time. A great gift for kids and friends Hourglass Instructions: You will receive 2 pieces of hourglass 3 minutes. 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