Best Time Management Tool: The sand timers for classroom or home 1/3/5/10/15/30/60 minute help your kids do things more efficiently and develop a strong sense of time. Useful and Practical: It can be used for hand-washing, teeth brushing, cooking, games, classroom, study, autism, visual, desk office decorative and teachers use timer.And this hour glass is also light, the size is suitable, very easy to move and carry on business trips. Acrylic Hourglass Timer:The sand timers are made of Acrylic, It is unbreakable and suitable for kids and each sand watch 3 min has a number of time mark. With high borosilicate glass inside and a protective cover on top, the plastic sand timer is pretty durable to use.