Small Tough-As-Nails Sandbag Set includes:

Small Tough-As-Nails Cordura Sandbag, 18″ x 30″ and holds 100 lb. of sand fully loaded; coarser-grained sand works best
Two 20″ x 36″ Small Liners (Yellow) to use as full size or partially filled to make a bunch of sandbag “weights”: fill, fold and secure with duct tape
The Complete Sandbag Training Course by Brian Jones