Impact Sandbags come in a variety of shapes and weights. They are used for securing the bases of light stands and set walls. This Impact Pro Sandbag Kit--Empty Saddle Sandbags - 27 lb (Set of 6)
from B&H Photo
includes six sandbags. Each sandbag has two wings, to allow draping over light stand legs. Each side of the bag has a hand strap for easy handling and hanging on hooks.
When filled with sand, each bag weighs approximately 27 lb. These are empty sandbags, each with a double zippered closure. Fill it with sand or small rocks upon arrival at location, and empty it at the end of the shoot -- no heavy shlepping or high shipping expenses.