Single-piece construction means no loose pegs or choking hazards Switch tracks and adapters allow for endless track combinations Promotes creativity and helps increase cognitive development Compatible with all major brands of wooden train tracks Curve pieces have tracks on both sides for extra versatility This set includes: (12) 6" wooden straight train tracks, (12) 6" wooden curved train tracks, (12) 3.5" wooden curved train tracks, (12) 3.5" wooden straight train tracks, (2) double prong adapters, (2) double hole adapters, (2) switch tracks (two holes, one prong), (2) switch tracks (two prongs, one hole)