Workout Sandbags filler bags are guaranteed NOT to leak. They have proven themselves in gyms, boxes, pro and college training facilities, and more. Their original design allows them to shift as a whole unit with the outer bag. The entire sand capacity of the outer bag is held by the filler bag. Adjustments are made by adding or removing sand. We recommend filler bags for any gym, box, team, or other commercial use. They will last you a lifetime with proper care, just like our outer bags. No chopping the sand load up into separate compartments. This is how our bags deliver a superior sandbag training workout. You will be amazed!
Above photo taken by a dojo owner in San Jose showing our "Snake" bags in action. Our filler bags are the same construction but a different shape.