**Rigamajig Simple Machines Add-On Kit** is a brand new set of Rigamajig components to expand Rigamajig Basic Builder Kit, the large-scale building kit conceived for hands-on play and STE(A)M leaning! Simple Machines Add-On Kit includes gears, a new wheel-pulley, levers, belts, cranks, and axles! - 57 parts total These thoughtfully crafted loose-parts were created with educators' feedback in mind with the goal to provide a new perspective and range of discovery, tinkering and exploration inside a classroom, on a playground, or in any play space. Now, young collaborators can mechanize their Rigamajigs, making simple or complex systems that exemplify the principles of mechanics, direction and force. Similar to Rigamajig Basic Builder Kit, the Simple Machines Add-On Kit lends itself not just to structures of machines, but also all kinds of sculptural creations! Simple Machines Add-On Kit is made and manufactured in the U.S. It is fabricated using the highest grade Baltic birch plywood and finished with a HAPS-free (Hazardouis Air Pollutant-free) finish, and the wingbolts, hexnuts, and brackets are made from a reinforced 100% recycled nylon. Simple Machines Add-On Kit is not compatible with Rigamajig Junior Kit.