Polyester Blend Designed to fit with Montlake patio cushion slip covers offered in multiple colors (slip covers Sold Separately). Cushion foam measures 25" x 18" x 4" thick High quality foam uses a dense core with a soft outer layer to provide just the right give for a firm but comfortable surface. One-Year limited Warranty Please note that foam will arrive vacuum packed and for Best results and ease of stuffing, the foam needs to be inserted into the slip cover immediately after opening.