Durable and Safe: This plastic hourglass timer is made of durable transparent acrylic and filled with fine sand in a variety of colors, and the sand runs smoothly. These sand clocks are durable and safe toys suitable for children. Useful and Practical: Use different sand glasses for different activities. 1 minute for brainstorm, 2 minutes for teeth brushing, 3 minutes for closing eyes and refreshing, and 5/10 minutes for reading the news or skimming a short story. Help your child complete tasks more efficiently and develop a strong sense of time.