A. SAFETY HOURGLASS TIMER: The large color 60-minute sand timer is made of high borosilicate glass and plastic material. Each 60-minute sand watch has a number of time marks, making it easy to distinguish which timer is for which usage. Size: 5.2 X 2.6 inch B. NON-BREAKABLE SAND TIMER: The hourglass outer layer is made of plastic and the inner one is made of glass, protected by a double layer. The hexagonal top caps are firm and durable, making it more sturdy and secure to reduce moms' worry C. TIME MANAGEMENT TOOL: The 60-minute sand timers for classroom can help your kids do things more efficiently and develop a sense of time. The 60-minute hourglass can be used for cooking, games, classroom, study, and desk office decoration D. WARM TIP: This 60-minute hourglass sand timer is mainly made for games, not a precision timing device, so there is time deviation