4 years & up. The Original Judy Clock is still a favorite amongst students and teachers. The Judy Clock makes learning to tell time simple and fun for children. Visible functioning gears maintain correct hour hand and minute hand relationships. Movable hands, visible functioning gears, and elapsed time bezel introduce children to concepts of time, motion, and cause/effect. Permanently assembled. Includes teacher's guide. 12 3/4" diameter x 13 1/2"H. Mini-clocks are sold separately.