Calibron 12 Brain Teaser - Very Difficult Design From 1933 - 12 Hardwood Pcs 12 Hardwood pieces with at least 4 different woods make up the set. New - now comes with cover. Comes unsolved. Your goal is to fit all the pcs into the large opening Extraordinarily difficult, yet it doesn't appear so at first Made in Hudson, Florida by Creative Crafthouse Originally designed by Theodore Edison, son of inventor Thomas, in 1933