Dear customer, Thank you for choosing our products. If there is any problem with our products, please contact us through the order information. We will be happy to serve you and solve it for you as soon as possible within 12 hours, thank you! The puzzles for adults and kids are 100% brand new high quality alloy material and exquisite processing ensures absolute durability and structure, do not rust and do not fade. The puzzle is designed to enhance kids' perseverance and deduction power for improved mind sharpness and alertness. It can help to relieve the pressure, exercise patience, expand thinking, spend time. This product aims at keep brain activities and Anti-Alzheimer's. It also training kids imagination, eye-hand coordination and shape recognition, eye coordination is also conducive to general physical coordination. It can not only provide us with a positive way of recreation and rest to release heavy stress, but also practise our intelligence a lot, make our more clever and confident. Relieve stress, relax, unlocking them may be takes a long time, which can also test fully your patience and attentive. It can also increase the difficulty according to their needs.