This is a 10 lb capacity Tenba Small Heavy Bag Sand
bags come in a variety of shapes and weights. They are used for
securing the bases of light stands and set walls. Many have handles, for
hanging on hooks or risers. Some have two wings, to allow draping over
light stand legs.
Most are Cordura nylon, some are vinyl covered and waterproof.
Some
models of sandbags are shipped empty, for convenience and economy. They
can be filled with sand, or any type of weight you provide, and emptied
for storage, or transport.