KINGOU Wooden square lock Puzzle Burr Puzzles Brain Teaser Intellectual Jigsaw Toy Magic Cube Name: Wooden Cube Puzzle. Size: 2.36 x 2.36 x 2.36 (inch) Recommended for ages 5 & up, children should be used under adult supervision. It is a puzzle that will entertain and challenge all ages. Hard to take it apart, but harder to assemble. Difficulty Rated:  . When assembling requires careful observation and thinking, analyze its internal structure.Our mind puzzle help to exercise brain, develop intelligence, improve problem-solving ability, and also relieve pressure. To make it challenging and fun, parcel without paper instructions, We will send emails for you to tell the secret solution. If you need help, please contact us.