FatSac Fillable Weight BagSimply fill the bag with water, sand, pebbles or other material to quickly and easily add flexible weight to your boat. Convenient grab handle. Features Any material can be used to fill the Sac such as water, rocks, sand, and metal slugs Fillable Sac weighs 50 pounds when filled with water (increased weight when filled with sand or other material) To fill plunge the bag under water until full, then screw in the plug When done, empty the contents and