The gears are made from solid mahogany, walnut and maple hardwood and the base from laminated birch with a walnut top. The gears have a tough lacquer finish while the sliding surfaces are finished in a non-toxic low friction oil. The gears may be moved around on the board, with dozens of combinations being possible. As the student manipulates the gears a basic understanding of gears follows. The base is 1" thick while the board is 10"x12". This set includes 3 gears.