Turn your Quadrilla Marble Run Sets into something bigger, better, and curvier with the Quadrilla Expansion Set for Rail, Twist, and Twist & Rail Sets! Perfect for adding value to the larger Quadrilla marble run sets, the Quadrilla Expansion Set for Rail, Twist, and Twist & Rail Sets includes 21 different pieces for building, including blocks, risers, rails, large and small funnels and much more. Plus, this Quadrilla Expansion Set for Rail, Twist, and Twist & Rail Sets includes an instruction guide for building 22 new layouts. The perfect addition to the Quadrilla Marble Run Toys, kids will be on the fast track to imaginative marble play with the Quadrilla Expansion Set for Rail, Twist, and Twist & Rail Sets!