Century Fitness Hydrocore Water-filled Heavy Training Bags! Century Fitness Hydrocore Water-filled Training Bags allow you to vary the weight so they"ll accommodate everyone in your household: Unique 8" diameter water core surrounded by high impact polyurethane foam reduces risk of injury from an overstuffed bag; Easy fill water core allows you to customize bag weight; Delivers a realistic feel of hitting an opponent; Durable black polyester backed vinyl covering; Four 2" polypropylene web straps with a test weight of 1,500 lbs. each; Sturdy steel chains with 2" steel ring for hanging; Bottom tie down loop. Approx. 70 lbs. when filled with water. 13" diam. x 3"4"h. Get your weight-adjustable Training Bag now! AVAILABLE SEPARATELY: X-Large - word search in our Store for "Water-Filled Heavy Bag". Century Fitness Large Hydrocore Water-Filled Heavy Bag, Black