Steel alloy track with Black roadbed; 4/Card, 22"" Radius curved track is best used to make relatively wide railroad curves, This track accommodates longer locomotives and rolling stock, and permits mainline operation at higher speeds, It can be placed on the outside of 18"" radius curved E-Z Track for double-track mainline realism, Four pieces of track make up one quarter (90 degrees) of a 44"" diameter circle, SKU: SPWS4705