This empty 77 lb saddle bag-design Sandbag from Kupo is filled with sand by the purchaser and used to stabilize a stand by draping it over the legs and preventing the top-heavy light stand from falling over, while it is also used as a counterweight on a boom arm to balance a light fixture's weight. The bag is made from black Cordex textured nylon, and the underside has a polyurethane coating which makes it water resistant and durable. Four integrated ladder-lock buckles allow you to tighten up the straps to keep the sandbag securely attached.