The Pro X Series Tube Sac was designed to fit in the in-floor central ski locker, or in the bow walk-through found in most open bow boats. Placing almost 400 pounds of ballast further forward in the boat not only makes for a drastic difference in wake size and firmness, it also leads to a wakeboard boat that is more nimble on the water because of the even weight distribution. That means you get all the benefits of additional ballast, along with great handling and fuel economy. Specifications Dimensions: 10 in. x 16 in. x 62 in. Capacity: 370+ lbs.