SMAI Strongman Sandbag: Redesigned for Ultimate Strength and Durability. The SMAI Strongman Sandbag has been redesigned from the ground up to be tougher and stronger, making it the best strongman bag available. Upgraded features include: Double 1000D Cardura construction Double lined, heavy duty outer bag Heavy duty liner bag 1 inch commercial grade velcro Double stitched pressure seams 1inch internal webbing around the full perimeter, which spreads the bag load across a bigger surface and takes