Our bags are quality constructed with full zipper and Velcro closures. They consist of two vantage points of contact with both mid and end attack points. All bag sets come with 3 bladders large, medium, and small. There is ample room to add bladders (not included) to increase potential weight to 60 lb. + Note this product is not provided with sand or stone for weight. We have limited stock of these bags in London Ontario and ship all products out of our South Western Ontario location