I filled the bag with sand, which allowed me to achieve a weight of 22 kg. It seems that the maximum stated weight of 35 kg refers to heavier filling. The inner bags are quite delicate, so I recommend wrapping them in plastic or putting them inside a stronger bag—one of mine started to come apart at the seam. The material of the outer bag seems solid, but the zipper has no special protection (usually there is velcro), so for safety I taped it up. The straps have a rather rough fabric, so with dynamic movements, they can chafe the skin around the joints (especially with certain grips). Considering the price, I find this product worth recommending.