Polyester Dimensions: 18 in W x 36.5 in L x 3.5 in T (seat cushion is 18 in W x 16.5 in L and seat back is 18 in W x 20 in L) Eco-friendly C0 Treatment Filled with partially recycled polyester fiber fill that helps retain shape over time Fits most standard dining, stacking, or bistro chairs 100% polyester outdoor fabric treated with enhanced UV protection to resist fading