The base of the bag will be empty upon delivery.
You can fill the base of the bag with either sand or water (or both) depending on what you're looking for in terms of weight and convenience.
We recommend going with sand for the best experience during your workouts.
Water is much more convenient and will be easier to fill, empty, and to move around when needed. However, the bag will be lighter with water (250 lbs) which means it may move during your workouts.
To get the best boxing experience, we recommend filling the bag with sand instead to ensure that the base is heavier (350 lbs).
For extra weight, water can be added to the sand, which brings the weight up to 450 lbs.