This heavy duty workout sandbag is a training gear. The inner bag is polyester Cordura 1000D with PVC coating, and the outer bag is nylon 1050D Cordura. Built with high-quality materials and advanced sealing, it's durable, waterproof, and sand-proof, ideal for all-around training. | Vevor | | Workout Sandbag, Heavy Duty Workout Power Bags with Handles, 50-125 lbs Adjustable Slam Bag | Black | Best Buy