Use flexible foam inclines to easily change track elevations on curves or straights. The SubTerrain System's pre-cut Inclines remove the guesswork and complicated calculations. Stack the pre-cut Inclines on top of Risers for quick and easy elevation changes. This 4% incline rises 4 inches in 8 feet. Each piece is 2 inches wide x 24 inches long.FeaturesLandscaping FoamFor use with your scale model railroad.