UGEARS Aero Clock 3D Wooden Puzzles for Adults and Kids – Laser-Cut 3D Puzzle Clock to Build – Elegant Outlook DIY Wooden Puzzle Mechanical Clock Kit – Wall Clock with Pendulum Wood Model Kit

The Aero Clock is one of the most sophisticated and ingenious model making kits. The assembled wooden clock kit is driven by the force of gravity pulling on a bag you fill with sand or salt. Raise the bag on its pulleys to wind the 3D wall clock. As the weight slowly descends, it rotates a drive gear that rotates an escape wheel through a reducer.
Product Dimensions 29.53 x 18.5 x 6.5 inches