Trapezoid welted outdoor chair cushion 18 inch wide in the front, 16 inch wide at the back, 17 inches deep and 3 inches thick.Plush, soft but strong chair seat cushion. Cushion has piping all across the sides for strength. Contains zippers for removing covers. Covers are machine washable. Ties in the back area for securing on chairs. Made with commercial hotel standards. Made from weatherproof and colorfast Sunbrella® fabric. Fits most outdoor patio chairs. Dimensions: 18FW x 16BW x 17D x 3H.