3/8" x 2-3/4" top x 3-1/2" bottom Foam Roadbed.  This auction is for 5 pieces 48" long (20' total), black in color. This roadbed is very dense foam, much firmer than the Woodland Scenics foam, and has great sound deadening qualities. A great substitute for Homasote or cork. I can custom cut widths in this material for different scales or yard mats. Please ask questions before you buy.. I will send you a sample, just email me with your name and address thru the ask a question option....