Jerry Slocum's new book on ancient puzzle padlocks

Jerry Slocum and  Dic Sonneveld  just finished their new book that tells the story of the oldest secret-opening puzzles ever found, from the 2nd century BC to the 4th century AD. It shows high quality sets of photos of 156 Mask Padlocks that we found in Museums, Libraries and private collections. This is the first book about these incredible puzzles.