Sandbags have been stabilizing light stands for a long time, but this Galaxy Audio Life Saver Sandbag has been designed with sound equipment in mind. It has a unique doughnut shape that keeps the bag from sliding off the mic, speaker, or light stand. The Life Saver is made from reinforced vinyl and weighs 38 lb when filled with sand and 22 lb when filled with water (neither sand nor water is included). It's particularly effective when used to stabilize a mic stand with a boom.