Freestanding reflex bag perfect for improving hand/eye coordination, speed, agility.Great upper body workout.Strong steel spring allows for fast action punching, slipping, and counter-punching.Base fills with 60 pounds of water or sand. (Sand is preferred); adjustable from 5 to 7 feet tall. Includes black speed bag constructed of Soft Sponge Solid Ball that does not need to be inflated and is moisture proof.