Thames & Kosmos Simple Machines Science Experiment & Model Building Kit, Introduction To Mechanical Physics, Build 26 Models To Investigate The 6

Thames & Kosmos Mechanical Engineering: Machines & Vehicles STEM Experiment Kit | Build 20 Mechanical Models, Explore Physics Of Force & Motion |

PATHFINDERS STEM Kit - Hydraulic Robotic Arm | Wooden Building Kit For Kids Ages 8-12 | Mechanical Engineering Toy | Hands-On STEM Project For Boys

UGEARS V8 Engine Model Kit - 3D Wooden Puzzles For Adults, 3D Puzzle Model Engine Kit, DIY Kits Gifts For Engineers For Christmas, Wooden Model Kits