Safety Sand Timer: The Mini 2 minute sand timer made by skin-friendly,high borosilicate glass and acrylic material. And each one has passed the quality-check. Of course,our sand glass will be used easily. Unbreakable Material: The outer material is made of hard acrylic and the inner one is made of glass,which is protected by double layer. Moreover, the silver textured top caps are sturdy and durable,so it will not easily hurt your children.