A new expansion kit compatible with the entire Action-Reaction range so you can create even more spectacular circuits! • Construct thrilling circuits, defy gravity with the incredible loop-the-loop and watch as your marbles speed off at high velocity! • Fire up your imagination and create even more exciting circuits! • A new expansion kit compatible with the entire Action-Reaction range! • Add fun special effects to your circuits and further sharpen your ability to hit the bulls eye! • Create even more spectacular circuits and jump into the world of physics in a simple and entertaining way!