WEIGHTED BAGS BALLAST ON THE SAND FOR TENTS AND PAVILIONS UMBRELLAS SET OF 4!!! HIGH QUALITY MATERIAL: Oxford 1680D fabric with PVC coating, 300% stronger than most on the market, makes the weight durable and waterproof. DOUBLE ZIPPER COMPARTMENTS: Each bag has two zippered sections to fill with sand, gravel or any preferred contents. TWO-CYLINDER BAG: Each seam of the bag is double stitched to ensure durability and comes with one Velcro strap to hold and ease of use to tie. HOLD 18KG WEIGHT: Bags can withstand up to 40 pounds (18 kg) of weight in sand, rock, earth and other contents. Use wherever you have a canopy: markets, campsites, tail flaps, picnics, festivals, celebrations, sporting events, beach, etc. Widely used: Ballast bags are a must for camping, traveling, picnics, festivals, outdoor fairs, parties, barbecues, sporting events, the beach and wherever you need a canopy or a secured tent.