Resin Umbrella Base with Filling Cap (White) These resin bases are specifically designed to fit any Grosfillex 28 inch or 32 inch square, 38 inch round folding table, and large 48 inch round resin tables. Their resin bases are durable, weather resistant, attractive, and long lasting. The solid one-piece molded construction is 100% prime resinmaterial naturally impervious to salt air, chlorine, and most common food and environmental stains. These bases are not pre-filled. You must fill with water or sand to weigh 35 or 40 pounds for stability. Filling cap included. Color= White.