Ugears mechanical models are a combination of easy-to-assemble mechanical puzzles along with the magical movement of wooden gears. Great mechanics based on the real-life designs UGEARS Tractor and Trailer Mechanical 3D Puzzle is a fully realistic, powerful and original mechanical model. Ugears Tractor has 3-step transmission: use “low” to move the freight to the location, use “stop” for unloading or switch to “sport” gear to participate in Tractor Races. An outstanding design, a rubber engine and mechanical power will surprise you. Made from eco-friendly plywood. Tractor size assembled Size assembled 7.9*3.4*5.4in (201*87*137 mm) Trailer Size assembled 8.2*4*3.8in (209*101*96 mm) Estimated assembly time 3 to 4 hours for the tractor and trailer set. Includes a detailed step-by-step illustrated manual with instructions in 10 languages. Perfect from 14 years.