Introduce children aged 8 and up to concepts of levers, pulley systems, resistance, effort, and mechanical advantages with the KID K'Nex STEM Explorations: Levers & Pulleys Building Set. With this set of 139 K'Nex pieces, kids can build simple machines such as a scale (lever), a wheelbarrow, and a sailboat. By constructing these simple machines, children stimulate their imagination as well as their hand-eye coordination, spatial awareness, and problem-solving skills. This building set also includes downloadable worksheets, allowing for various activities with the building models.