This is 1 new professional studio lighting PBL heavy duty constructed sand bags. The unique saddlebag design can be draped over or clamped onto light stand legs, support systems and booms to provide extra stability and safty. With dual 10 1/4in x 9 1/4in interior compartments. These heavy duty bags can be filled and emptied over and over again with sand, gravel or even nuts and bolts. These sandbag will prove to be an indispensible part of your studio system for years to come. A must for location work.