Neewer&reg; SP-WCM Photo Video Studio Softbox Photo Holding Panel Boom Arm Bar Water Bag with 6 Outer Pouches (Black) Ideal design for stabilizing light stands, boom stands, stage, outdoor or studio. Light weight, Versatile and Compact. Strong and durable, with 6 outer pouches to hold 6 bottles of water. Strengthened by PVC Pad, which can be filled, emptied, and refilled as many as you wish. Simply hook it to a light boom arm or put on boom light stand. Convenient Pre-measured Weight Gradation: Measured by water. Note: the boom arm, umbrella and water are not included!