Hot Wheels Track Builder Volcano Blowout Stunt Set The electronic stunt is perfect for boys who crave more action when building out their ultimate track sets Race by a seemingly dormant volcano and watch out, the rumble noises sound like trouble! You may pass twice, but a third time will cause a volcano eruption! Electronic accessory enhances existing sets and offers easy ways to connect Combine with the other stunts and packs in the Track Builder line (sold separately)