This hourglass set contains 4 hourglasses in different colors, incl. 3-minute hourglass, 5-minute hourglass, 10-minute hourglass and 20-minute hourglass. It is ideal for reading, cooking and baking, brushing teeth, playing and training timing. Our timer is made of resistant PVC, borosilicate glass, sea sand and protective cover, which means that the timer cannot be easily broken and the service life lasts longer. The hourglass is a very effective visual cue that improves attention and time management. It helps your children to make things more efficient and develop a strong sense of time. The timepiece can be used for cooking, playing, classrooms, parenting and training. Can also be used as a home or office decoration and timing tool. Great gift for kids and friends. Hourglass has matching black shaped end caps and clear thick wall. Each timer is provided with colored sand and a clear digital display for easy identification. Note: These children's hourglass timers are not precision timing devices, so there will be time deviations. More importantly, please do not scratch the words on the glass with anything to prevent the words from falling.