SAFETY HOURGLASS SAND TIMER: The large sand timer 3 minute made by friendly high borosilicate glass,100% hand-blown made clear glass. And each one has a number of time mark. You can easy to distinguish which timer for which usage. PRACTICAL SAND TIMER: It is both a hourglass artwork and a useful time tool. Our sand hourglass timer provides an optimal time frame for work and rest. Meanwhile, fit for your Home, Office, Desk, Science, and Education. Makes a thoughtful gift for any occasion. DURABLE DESIGN: The clear hourglass is made of tough borosilicate glass which makes the sand hourglass timer not easily broken, and it will not easily cut your children's hands