Usage Tips:Shock Resistant Sand Timer: Made of durable PVC, high borosilicate glass, sand and protective cover, which ensures the sand timer is not easily broken, durable to use. Widely Use: Perfect for games, classroom use, cooking, exercise, kids brushing (toothbrush), toddler playtime, etc. It can also be used as a decoration. A good gift for children and friends. Take note: This sand timer is not a precise timing device, so there is a time deviation. Moreover, please do not use anything to scratch the words on the glass to prevent the words from falling off. Warm tips: 1. Glass becomes fragile under sharp blowing, carefully placed. 2. As the timer cannot replace the mechanical watch, please allow +/- 10% deviation. 3. Sand into powder Please let it stick or absorb on the glass. Just leave it to dry in the sun or crack. 4. Under adult supervision when the child is under 3 years old. Package: 1 X Glass Sand includes: