These STEM building toys bring different engineering projects into hands-on play, giving boys and girls a variety of models to assemble and investigate. 6-in-1 STEM Educational Building Kit for Kids: an aircraft model, obstacle-avoiding robot, tracked tank, wind car, six-wheel off-road vehicle and solar-powered car. Robot Building Meets Moving Models: Discover the connection between building and motion with a robot building kit that includes more than a robot.