The Original Soft Medicine Ball – now bigger and heavier! Dynamax Atlas medicine balls; range from 20 lbs to 150 lbs, and are designed for high-intensity weight training. All balls are 22″ in diameter, moisture resistant, and are made from 70% post-consumer recycled materials. The design and construction ensures that they will remain dimensionally stable and balanced. Soft shell construction and balanced, uniform weight make it easy to handle. Filler material provides even weight distribution and helps maintain shape.