The Leofoto Universal Tripod Rock Bag creates a compartment between the legs under the tripod platform. This open compartment can be used to place objects with weight to weight the tripod. This can be stones or some sand, but also any other object is possible. By increasing the pressure on the legs, the stability of the tripod is increased. This can be useful when you want to photograph in strong winds. The advantage of a weighted compartment where the weight is distributed over the three legs is that the extra weight cannot start swinging in the wind. As is the case with a sandbag attached to the bottom of the tripod platform. You can also determine the extra weight yourself, up to a maximum of 44 pounds.