Geared for Time® Clock: Classroom Kit - 1 Demonstration & 24 Student Clocks The Geared for TimeTM demonstration clock has the sun and moon wheel turn as the clock hands move in a 12 hour period to illustrate day and night. Includes a removable linear time line with magnets. Activity guide included. Measures 12". The student clocks are 4" replicas of the demonstration clock without the linear time line.