The Ultimate is a dizzying mishmash of curves, spirals, and drops which will put your marbles through a whirlwind marble race! The Ultimate is Quadrilla's largest marble run set, with two spiral funnels, twelve curved rails, ten accelerators, and a large assortment of building blocks. Quadrilla's The Ultimate can be combined seamlessly with Quadrilla's other marble run sets. All Quadrilla marble run sets are crafted with high quality birch and rubber wood for long-lasting marble racing fun! For ages four years and up.