The Discovery™ DIY Model Hybrid Engine Kit lets kids build a working transparent 3-cylinder hybrid engine model while exploring real automotive engineering concepts through hands-on STEM learning. ... Using 116 pieces, builders assemble a 2-in-1 system that demonstrates concepts behind electric and combustion engine systems, with moving pistons, a rotating crankshaft, opening valves, spinning gears, and a glowing electric motor inside a transparent housing that reveals everything in motion. The included full-color engineering guide provides step-by-step assembly instructions while introducing concepts behind hybrid technology and modern engine systems, making it an ideal hands-on STEM experience for curious builders ages 8 and up.