The Greendale Home Fashions Bistro Cushions feature two string ties to secure to chairs, and a center circle tack to secure foam cushioning in place without bunching or migrating. Each set includes four 18 inch round cushions made from a 100% polyester, UV coated material that is fade, stain and water resistant. The cushion's poly fiber fill is made from 100% recycled, post-consumer plastic bottles, and overstuffed for added comfort, strength and durability. A variety of modern prints are available.