Fit my son's Peanuts Snoopy G gauge track perfectly. The clips that attach the tracks are pictured wrong in the listing but are G gauge compatible. These help build the expansion when you buy the switch tracks.
Tracks do not stay together and the train goes around once and the tracks come apart. I bought these tracks to be used with the Lionel Polar Express Train and it is very disappointing. I would not recommend this train based on the crappy tracks.
Track was great, but it does not fit with the track that came with our original 24-piece Holiday Train Set. A couple of our original pieces disappeared, and we are searching for replacement track, but we are going to have to replace it all since the new track is not compatible.