SAFE HOURGLASS: The large colored 60-minute hourglass is made of friendly high borosilicate glass and plastic material. And each sand timer 60 min has a number of time markings, making it easy to distinguish which timer is for which application. Size: 13.2 x 6.6 cm. UNBREAKABLE HOURGLASS: The outer layer of the hourglass is made of friendly plastic and the inner layer is made of glass, which is protected by double layers. And the hexagonal top caps are solid and durable, so it is more robust and safe, avoiding mothers' worries. BEST TIME MANAGEMENT TOOL: Classroom sand timers 60 minutes help your children do things more efficiently and develop a strong sense of time. The 60-minute hourglass can be used for cooking, games, classroom, study, desk decoration. WARM TIP: This 60-minute hourglass is mainly made for games, which is not an accurate time measuring device, so there are time deviations.