Alliance Gator NGG3030-04050 4' x 50' 30-30 Biaxial Grid - The Gator 30-30 Grid is a biaxial geogrid that provides strength and longevity. It prevents failure of the internal structure of landing areas and retaining walls. It has a high molecular weight as well as high-tenacity polyester yarns which are woven in tension and finished with a PVC coating. Its design allows it to be installed in both directions.