Large-scale trial-and-error construction that young children can really get their hands on! Creative track building allows children to think, predict, test, observe results, solve problems, adjust, and try again. A very satisfying process for young engineers who are discovering how to make their ideas - and their world - work. Made of smooth beechwood with 1.5" wide tracks. Long ramps are 12.5". Sets include 1.75" diameter balls. Serious fun, with ramps and rollways galore! 30 pieces including 3 balls. Lots of ramps, curves, and stabilizing connector blocks.