Bridge the gap with the “GraviTrax Bridges Expansion” set and keep your marble run rolling! Bridge track sections! Bypass large gaps with Bridges. Combine the Bridges with your GraviTrax Starter-Set for even more variety by interlinking track sections for really spectacular results. How many unique track designs will you create? Comes complete with 3 adjustable-length Bridges, 2 long thin tracks, 2 long slow tracks, 1 long track, 2 medium tracks, 3 short tracks and instructions.