Hyperwear Fit Ruck Convertible Sandbag Training Rucksack for Sandbag Exercise Ultimate sandbag training versatility in a super sandbag backpack for Strength Training Outdoors Simply load it up, strap it on your back and head outdoors to start your rucking workout Rucking: Fit RUCK 20 lb package includes two EMPTY SandBells 8 LB, 12 LB. (purchase sand separately and fill) Convertible, patented, ultimate sandbag training tool has multiple handles Perfect for outdoor boot camp fitness strength training