The lock may look simple, but it contains lots of mysteries. Use your brain, exercise your patience, is unable to untie the knot, but as long as the master of the structure, is sure to solve. Easy to take apart and difficult to reassemble. Not only it can enhance your ability, and can even be an extraordinary plan. Suit for both children and adult. Challenge your mind and patience. Cautions: 1. Children must be used it under the adult's tutelage. 2. Don't throw the away to each other. 3. Don't use it if there is any problem. 4. Don't keep the toy in the mouth to prevent children devour small parts in the toy. Maintenance: Handle with care, avoid desiccation, being washed. Package Contents: Set of 4 Wood Classic Brain Teaser Jigsaw Lock Puzzle 1Benefits: If you order the wooden cube puzzles, it will be a great opportunity for parents and children interact together which can enhance closeness. Moreover, it can challenge your mind, patience and help develop the intellect.Perfect for IQ development and imagination. (2)Multifunctions: Relief stress, develop intelligence, hand-eye co-ordination skills, improve dexterity, foster logic thinking, parent-child interaction, prevent Alzheimer's and more. All in all, this toy is to make your life quite interesting. 3Suitable for All Ages: With the recreational function, the wooden cube puzzles are suitable for all ages. Such as office workers,children and the old. 4High Material: Excellent selection of natural wood, wear-resistant and durable,and use environmental protection wood lacquer, non-toxic and odourless, smooth and resilient. 5Great Variety in Designs: Kongming locks come in different shapes and sizes, with different internal structures. 30 different designs, 30 different fun.