W.R. Meadows 1703035100 10' x 3-1/2" x 1/2" X-Foam Tile Ledger Board is a flexible, lightweight, non-staining, polypropylene, closed-cell expansion joint filler. It is a chemical-resistant, ultraviolet stable, non-absorbent, low density, cost-effective, compressible foam that offers an extended service life in both interior and exterior applications.