Filbur FC-9899 Replacement DE Grid Kit for Sta Rite System 3 SD DE Grid Set 53-Square Feet Swimming Pool Filter High quality durable polypropylene cloth grid Stronger, more durable frames outlast the competition; reinforced frames and connections 100 percent polypropylene cloth finished to our exact standards assures precise control of filtration efficiency, dirt holding and decake release Fewer glue joints and re-enforced spines increase the torsional strength and prevent snapping Sold as complete kits