MECHANICAL TRANSMISSION TECHNOLOGY: Each fine part and the gear are interlocked one by one. It has an open spiral element that can be rotated and opened. The bottom slot switch can rotate the cover plate. The bottom is equipped with a removable baffle for easy access. DIY EXPERIENCE: Building a wooden puzzle toy will stimulate your childs ability to plan and build their own structure like a true engineer. Entertaining and engaging brain teasers for adults and kids. Manufacturered by Yamix. LEISURE TOYS: Adults also need to release their stress through games. Instead of using video games in mobile computers real toys are used to relieve their stress. BEST GIFT CHOICE: 3D wooden puzzles for adults and kids will always be a welcome gift. Great gift for birthday Christmas Thanksgiving Valentines Day boy girl friend family members. HIGH QUALITY AND NATUAL: Made of ecyclable and safe natural birch safest and entertaining 3d wooden puzzles for kids and adults. Finished model size about 12.5 x 9.5 x 24cm.