Everlast EverFlex Freestanding Heavy Bag (Black) Combines our synthetic bags with reinforced, high density LDPE base that provides maximum flexibility with outstanding durability and resilience Precisely engineered freestanding bag with spring action response Flexible collar system allows the bag to absorb substantial impact without base movement 3 height adjustments allow bag to stand from 52" to a full 70" tall Base holds as much as 24 gallons of water (approx. 200 lbs.) for extra sturdy use