partially assembled Lego Technic models next to their instruction manual

partially assembled Lego Technic models next to their instruction manual. The model on the left features a black, red, and blue structure with visible pins and beams. The lower model is gray with a series of white discs aligned along a gray beam, connected to blue gears. A section of the instruction manual is visible with technical drawings illustrating the assembly process, including internal mechanisms with springs and gears. Bags of Lego parts are visible on the left.