Original Mini Hoberman Sphere - Grows from 6" to 12" instantly! (Linking Rings) Fascinating expanding ball in bright rainbow colors is a fun toy for indoor and outdoor play! Opens up from 6 inches to a whopping 12 inches instantly! No assembly required! Toss back and forth with a friend, and try to keep it from collapsing! Or balance it on your head as you try to walk! Great for a counting or geometry tool! How many triangles and you spot? Recommended for ages 4+.