The Riverstone Shade Cloth System is designed to offer easy to use, shade producing cloth that is UV stable and will last for several years in the hottest environments. All our woven shade cloths are proudly made from Black woven polypropylene strands in the USA. Each shade cloth comes with brass grommets for securing the shade cloth. the grommets are placed approximately 2 ft. apart around the perimeter of the each shade cloth. the percentage listed indicates the amount of shade that is being provided. This also reflects how tightly woven the shade cloths are.5 year limited warranty